Multi-block copolymer process using polar solvents

ABSTRACT

A process for forming a high molecular weight, multi-block copolymer comprising two or more chemically distinguishable segments or blocks, the process comprising polymerizing one or more olefin monomers in the presence of a chain shuttling agent and a catalyst composition comprising two or more olefin polymerization catalysts capable of preparing polymers having differing chemical or physical properties under equivalent polymerization conditions, or a catalyst composition comprising at least one olefin polymerization catalyst containing multiple active catalyst sites capable of preparing polymers having differing chemical or physical properties.

BACKGROUND OF THE INVENTION

The present invention relates to a process for preparing multi-blockcopolymers employing polar solvents. Multi-block copolymers andpolymeric blends comprising the same are usefully employed in thepreparation of solid articles such as moldings, films, sheets, andfoamed objects by molding, extruding, or other processes, and are usefulas components or ingredients in laminates, polymeric blends, and otherend uses. The polymers comprise two or more differing regions orsegments (blocks) differing in physical or chemical properties, such ascrystallinity, tacticity, chain branching, and/or monomer insertionerrors, thereby causing the polymer to possess unique physicalproperties. The resulting products are used in the manufacture ofcomponents for automobiles, such as profiles, bumpers and trim parts;packaging materials; electric cable insulation, adhesives, and otherapplications.

It is known in the art to prepare multi-block copolymers from one ormore monomers by the use of chain shuttling agents under suitablepolymerization techniques, especially continuous solution polymerizationconditions at relatively high monomer conversions. Preferred processesemploy two catalysts having differing comonomer incorporation propertiesand a chain shuttling agent such as organoaluminum and organozinccompounds. Examples include WO2005/904025, WO2005/904026, andWO2005/904027, as well as Science, 312, 714-719 (2006). Solvents for theforegoing processes generally include C₄₋₁₀ hydrocarbons, especiallyalkanes such as hexane or mixtures of alkanes, as well as one or more ofthe monomers employed in the polymerization. In addition, toluene wasemployed in WO2005/904025 in designed experiments to identify suitablecatalysts for chain shuttling polymerizations. In general, chainshuttling properties of aluminum compounds, especially trialkyl aluminumcompounds, were found to be inferior to those of dialkyl zinc compoundsunder the conditions tested in these studies.

It would be desirable if there were provided an improved process forpreparing multi-block copolymers, especially linear multi-blockcopolymers of ethylene and one or more C₃₋₁₀ α-olefins, or propylene,4-methyl-1-pentene, or another C₄ or higher α-olefin(s), mixtures of twoor more C₃₋₁₀ α-olefins, and mixtures of ethylene, and/or propylene witha conjugated or non-conjugated C₄₋₂₀ diene, by the use of a shuttlingagent under chain shuttling polymerization conditions, characterized byimproved efficiency and productivity. In addition, it would be desirableto provide such an improved process that is capable of preparingmulti-block copolymers, especially linear multi-block copolymers, havingimproved (more narrow) molecular weight distribution employingorganoaluminum chain shuttling agents, especially trialkylaluminumcompounds. Finally, it would be desirable to provide an improved processfor preparing any of the foregoing desirable polymer products in ahighly productive, continuous solution polymerization process.

SUMMARY OF THE INVENTION

According to the present invention there are now provided a process forforming a high molecular weight, multi-block copolymer comprising two ormore chemically distinguishable segments or blocks, the processcomprising polymerizing one or more olefin monomers in the presence of achain shuttling agent and a catalyst composition comprising:

two or more olefin polymerization catalysts capable of preparingpolymers having differing chemical or physical properties underequivalent polymerization conditions,

or

a catalyst composition comprising at least one olefin polymerizationcatalyst containing multiple active catalyst sites capable of preparingpolymers having differing chemical or physical properties;

characterized in that the polymerization is conducted in the presence ofa solvent comprising a polar, aprotic organic liquid compound, having adielectric constant greater than 2.4, preferably greater than or equalto 2.8, most preferably greater than or equal to 3.0.

Preferably, the foregoing process takes the form of a continuoussolution process for forming multi-block copolymers, preferably linear,multi-block copolymers, of ethylene and one or more C₄₋₂₀ olefins, andmost especially ethylene and propylene, ethylene and a C₄₋₈ α-olefin, orpropylene and an optional C₄₋₈ α-olefin, using multiple catalysts underthe foregoing polymerization conditions. Under continuous solutionpolymerization conditions at high monomer conversion, especiallyethylene, in the presence of the foregoing solvents, shuttling from thechain shuttling agent to the catalyst is more advantaged compared tochain growth, due, it is believed to stabilization of the shuttlingagent/polymeryl pair combination, leading to highly efficient formationof multi-block copolymers, increased polymer molecular weights, andnarrow molecular weight distributions (Mw/Mn). Surprisingly, the chainshuttling properties of organoaluminum compounds, especiallytrialkylaluminums, under the present reaction conditions is generallysuperior to those obtainable by use of dialkylzinc chain shuttlingagents. An additional benefit from the use of the present polar aproticsolvents is a reduction of solution viscosity during the polymerization,allowing the attainment of increased conversions and solids contents inthe reactor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is the ¹H NMR spectrum of polymer prepared according tocomparative A.

FIG. 2 is the ¹H NMR spectrum of polymer prepared according to Example1.

DETAILED DESCRIPTION OF THE INVENTION

All references to the Periodic Table of the Elements herein shall referto the Periodic Table of the Elements, published and copyrighted by CRCPress, Inc., 2003. Also, any references to a Group or Groups shall be tothe Group or Groups reflected in this Periodic Table of the Elementsusing the IUPAC system for numbering groups. Unless stated to thecontrary, implicit from the context, or customary in the art, all partsand percents are based on weight and all test methods are current as ofthe filing date hereof. For purposes of United States patent practice,the contents of any patent, patent application, or publicationreferenced herein are hereby incorporated by reference in their entirety(or the equivalent US version thereof is so incorporated by reference)especially with respect to the disclosure of synthetic techniques,definitions (to the extent not inconsistent with any definitionsprovided herein) and general knowledge in the art.

The term “comprising” and derivatives thereof is not intended to excludethe presence of any additional component, step or procedure, whether ornot the same is disclosed herein. In order to avoid any doubt, allcompositions claimed herein through use of the term “comprising” mayinclude any additional additive, adjuvant, or compound whether polymericor otherwise, unless stated to the contrary. In contrast, the term,“consisting essentially of” excludes from the scope of any succeedingrecitation any other component, step or procedure, excepting those thatare not essential to operability. The term “consisting of” excludes anycomponent, step or procedure not specifically delineated or listed. Theterm “or”, unless stated otherwise, refers to the listed membersindividually as well as in any combination.

The term “polymer”, includes both conventional homopolymers, that is,homogeneous polymers prepared from a single monomer, and copolymers(interchangeably referred to herein as interpolymers), meaning polymersprepared by reaction of at least two monomers or otherwise containingchemically differentiated segments or blocks therein even if formed froma single monomer. More specifically, the term “polyethylene” includeshomopolymers of ethylene and copolymers of ethylene and one or more C₃₋₈α-olefins in which ethylene comprises at least 50 mole percent. The term“propylene copolymer” or “propylene interpolymer” means a copolymercomprising propylene and optionally one or more copolymerizablecomonomers, wherein propylene comprises a plurality of the polymerizedmonomer units of at least one block or segment in the polymer (thecrystalline block), preferably at least 90 mole percent, more preferablyat least 95 mole percent, and most preferably at least 98 mole percent.A polymer made primarily from a different α-olefin, such as4-methyl-1-pentene would be named similarly. The term “crystalline” ifemployed, refers to a polymer or polymer block that possesses a firstorder transition or crystalline melting point (Tm) as determined bydifferential scanning calorimetry (DSC) or equivalent technique. Theterm may be used interchangeably with the term “semicrystalline”. Theterm “amorphous” refers to a polymer lacking a crystalline melting pointor to one having a heat of fusion (ΔH_(f)) less than 1 J/g as determinedby DSC as described here-in-after. The term, “isotactic” or“syndiotactic” is defined as polymer repeat units having at least 70percent isotactic or syndiotactic pentads as determined by ¹³C-NMRanalysis. “Highly isotactic” or “highly syndiotactic” is defined aspolymer blocks having at least 90 percent isotactic or syndiotacticpentads. The term “tactic” is defined as polymer repeat units that areeither isotactic or syndiotactic and the term “highly tactic” refers topolymer repeat units that are either highly isotactic or highlysyndiotactic.

The term “multi-block copolymer” or “segmented copolymer” refers to apolymer comprising two or more chemically distinct regions or segments(referred to as “blocks”) preferably joined in a linear manner (linearmulti-block copolymer), that is, a polymer comprising chemicallydifferentiated units which are joined end-to-end with respect topolymerized ethylenic functionality, rather than in pendent or graftedfashion.

As used herein, the term “noncoordinating” means a substance (solvent,anion, cocatalyst or cocatalyst remnant) which either does notcoordinate to the catalyst precursor and the active catalytic speciesderived therefrom, or which is only weakly coordinated to such complexesor species, thereby remaining sufficiently labile to be displaced by anolefin, such that the ability of the catalyst to polymerize the olefinis not prevented. The material also should not interfere with thedesired polymeryl exchange between the chain shuttling agent and theactive catalyst(s), for example, by irreversibly reacting with the chainshuttling agent to produce an inert product incapable of chain transfer.

It has been discovered that polar solvents are surprisingly advantagedfor use in the processes described in the instant invention, especiallynoncoordinating, polar, aprotic solvents. As is well-known in the field,a solvent that carries hydrogen attached to oxygen as in a hydroxylgroup, nitrogen as in an amine group, or, more generally, any molecularsolvent that contains dissociable H⁺ cations is a protic solvent. Themolecules of such solvents can donate a proton. Conversely, aproticsolvents cannot donate a proton. Common examples of protic solventsinclude water, methanol, ethanol, formic acid, and hydrogen fluoride.Polar aprotic solvents generally have similar ion dissolving power as doprotic solvents but lack a dissociable H⁺ cation. These solventsgenerally have high dielectric constants and high polarity.

The dielectric constant, ∈_(r), of a material under given conditions isa measure of the extent to which it concentrates electrostatic lines offlux. It is the ratio of the amount of stored electrical energy when apotential is applied, relative to the permittivity of a vacuum, alsocalled relative permittivity. For the purposes of this invention, thevalues for dielectric constants are those measured at 20° C., accordingto the formula:

${ɛ_{r} = \frac{ɛ_{s}}{ɛ_{o}}},$where ∈_(s) is the static permittivity of the material, and ∈₀ is vacuumpermittivity. Vacuum permittivity is derived from Maxwell's equations byrelating the electric field intensity E to the electric flux density D.In vacuum (free space), the permittivity ∈ is ∈₀, and ∈_(r) equals 1.

The dielectric constant ∈_(r) can be measured for static electric fieldsas follows: first the capacitance of a test capacitor C_(o) is measuredwith vacuum between its plates. Then, the substance to be measured isplaced between the plates of the capacitor and the capacitance, C_(x) ismeasured. The dielectric constant can be then calculated as:

$ɛ_{r} = \frac{C_{x}}{C_{o}}$

While not wishing to be held to any particular theory of operation, itis believed that suitable solvents for use herein are non-coordinating,polar, aprotic compounds having sufficient polarity to help instabilizing the presumed 4-center intermediate formed between theshuttling agent and the active catalyst, without adversely affecting thepolymerization process or preventing polymerization from taking place.Additionally, it is believed that the use of solvents having elevatedpolarity or dielectric constant weaken the interaction of the activecatalyst site(s) with counterions resulting from the activation process,leading to an increased relative rate of chain shuttling. Preferredsolvents possess a dielectric constant from 2.5 to 50, more preferablyfrom 2.8 to 25.0 and most preferably from 3.0 to 20.

Examples of suitable solvents for use herein include hydrocarbons,especially o-xylene, ethylbenzene, 1,2,3-trimethylbenzene,1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, isopropylbenzene,1-methyl-2-ethylbenzene, and 1,2-diethylbenzene, as well as heteroatomcontaining compounds, including chlorobenzene, o-dichlorobenzene,chlorotoluene, 1-chloroethane, dichloromethane, 1,2-dichloroethane,1-chloroethene, 1-chloropropane, 1,1-dichloroethane, 1-chlorobutane,1-chloropentane, 1-chlorohexane, 1,1,1-trifluoroethane, difluoromethane,trifluoromethane, 1,1-difluoroethane, 1,1,1-trifluororethane,1,1,1,2-tetrafluoroethane, 1,1,1-trifluoropropane,1,1,1-trifluorobutane, 1,1,1-trifluoropentane, 1,1,1-trifluorohexane,1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluorobutane,fluorocyclobutane, difluorocyclobutane, trifluorocyclobutane,pentafluorocyclobutane, fluorocyclohexane, 1,2-difluorocyclohexane,1,3-difluorocyclohexane, fluorobenzene, o-difluorobenzene,m-difluorobenzene, p-difluorobenzene, fluorotoluene, difluorotoluene,1-chloro-1-fluoroethane, 1,2-dichlorofluororethane,dichlorofluoromethane, difluorochloromethane, 2-trifluoromethylpropane,tetrahydrofuran, methyl t-butyl ether, 2-butanone, diethylether,1,2-dimethoxyethane, ethylene glycol dibutyl ether; diethylene glycoldimethyl ether, diethylene glycol dibutyl ether, dichloromethane,1,4-dioxane, chloroform, sulfolane, dimethylformamide, anddimethylether.

Mixtures of the foregoing polar, aprotic compounds may be employed aswell as mixtures of one or more polar, aprotic compounds with one ormore non- or less-polar organic compounds, such as one or more organiccompounds having a dielectric constant less than 2.4.

Suitable olefin monomers for use in the present invention include linearand cyclic compounds containing one or more ethylenic unsaturations thatare capable of polymerization or copolymerization using coordinationpolymerization catalysts. The present process is ideally suited for thepolymerization of a single C₂₋₂₀ olefin, especially ethylene, as well asthe polymerization of two or more C₂₋₂₀ α-olefins, especially ethyleneand a C₃₋₈ α-olefin, or for the polymerization of one or more C₂₋₂₀α-olefins in combination with one or more C₄₋₂₀ cycloolefins ordiolefins. Suitable monomers for use according to the present inventionpreferably include ethylene, propylene, 1-butene, 4-methyl-1-pentene,1-hexene, 1-octene, or other aliphatic C₄₋₂₀ α-olefin, and optionallyone or more copolymerizable ethylenically unsaturated compounds,especially a conjugated or non-conjugated diene, provided that theobject of the invention, preparation of a multi-block copolymercontaining blocks of differing chemical properties, is obtained.Examples of suitable comonomer combinations include ethylene andstraight-chain or branched α-olefins of 3 to 20, preferably 3 to 8carbon atoms, such as propylene, 1-butene, 1-pentene, 3-methyl-1-butene,1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene,1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene;cycloolefins of 3 to 30, preferably 3 to 20 carbon atoms, such ascyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene,tetracyclododecene, and2-methyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene;diolefins and multi-olefins, such as butadiene, isoprene,4-methyl-1,3-pentadiene, 1,3-pentadiene, 1,4-pentadiene, 1,5-hexadiene,1,4-hexadiene, 1,3-hexadiene, 1,3-octadiene, 1,4-octadiene,1,5-octadiene, 1,6-octadiene, 1,7-octadiene, ethylidene norbornene,vinyl norbornene, dicyclopentadiene, 7-methyl-1,6-octadiene,4-ethylidene-8-methyl-1,7-nonadiene, and 5,9-dimethyl-1,4,8-decatriene;aromatic vinyl compounds such as mono or polyalkylstyrenes (includingstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene,o,p-dimethylstyrene, o-ethylstyrene, m-ethylstyrene and p-ethylstyrene),and functional group-containing derivatives, such as methoxystyrene,ethoxystyrene, vinylbenzoic acid, methyl vinylbenzoate, vinylbenzylacetate, hydroxystyrene, o-chlorostyrene, p-chlorostyrene,divinylbenzene, 3-phenylpropene, 4-phenylpropene, α-methylstyrene,vinylchloride, 1,2-difluoro-ethylene, 1,2-dichloroethylene,tetrafluoroethylene, and 3,3,3-trifluoro-1-propene. Highly desirably,the polymers comprise in polymerized form ethylene, propylene and/or1-octene.

Highly preferably the multi-block copolymer prepared according to thepresent process possesses a molecular weight distribution, Mw/Mn, ofless than 3.0, preferably less than 2.5, most preferably less than 2.0.In some embodiments of the invention some of the blocks are crystallinewhile others are amorphous, for example blocks of high densitypolyethylene and blocks of linear low density polyethylene. In otherembodiments of the invention some of the blocks are tactic, especiallyisotactic, more preferably highly isotactic, and others are atactic. Instill other embodiments of the invention, some blocks are highlyregular, isotactic polypropylene and other blocks containirregularities, especially blocks comprising polypropylene containingregio-irregular monomer insertions which are 3,1-insertions, leading tochain straightening of the resulting polymer. The resulting blocks arerelatively amorphous, compared to the tactic polypropylene blocks.

The difference in various monomer addition geometries herein isillustrated by the following diagram using propylene as a representativemonomer, with the active catalyst site designated as Cat and thepreviously formed polymer chain designated by Polymer:

Because the respective distinguishable segments or blocks are joinedinto single polymer chains, the polymer cannot be completelyfractionated using standard selective extraction techniques. Forexample, polymers containing regions that are high density polyethylene(for example ethylene homopolymer) and regions or blocks that are lowdensity polyethylene (for example ethylene/C₃₋₈ α-olefin copolymers) orpolymers with highly tactic blocks and blocks containing regio-irregular2,1- or 3,1-monomer insertion cannot be completely selectively extractedor fractionated using differing solvents. In a preferred embodiment thequantity of extractable polymer using either a dialkyl ether- or analkane-solvent is less than 10 percent, preferably less than 7 percent,more preferably less than 5 percent and most preferably less than 2percent of the total polymer weight.

As used herein with respect to a chemical compound, unless specificallyindicated otherwise, the singular includes all isomeric forms and viceversa (for example, “hexane”, includes all isomers of hexaneindividually or collectively). The terms “compound” and “complex” areused interchangeably herein to refer to organic-, inorganic- andorganometal compounds. The term, “atom” refers to the smallestconstituent of an element regardless of ionic state, that is, whether ornot the same bears a charge or partial charge or is bonded to anotheratom. The term “heteroatom” refers to an atom other than carbon orhydrogen. Preferred heteroatoms include: F, Cl, Br, N, O, P, B, S, Si,Sb, Al, Sn, As, Se and Ge.

The term, “hydrocarbyl” refers to univalent substituents containing onlyhydrogen and carbon atoms, including branched or unbranched, saturatedor unsaturated, cyclic, polycyclic or noncyclic species. Examplesinclude alkyl-, cycloalkyl-, alkenyl-, alkadienyl-, cycloalkenyl-,cycloalkadienyl-, aryl-, and alkynyl-groups. “Substituted hydrocarbyl”refers to a hydrocarbyl group that is substituted with one or morenonhydrocarbyl substituent groups. The terms, “heteroatom containinghydrocarbyl” or “heterohydrocarbyl” refer to univalent groups in whichat least one atom other than hydrogen or carbon is present along withone or more carbon atom and one or more hydrogen atoms. The term“heterocarbyl” refers to groups containing one or more carbon atoms andone or more heteroatoms and no hydrogen atoms. The bond between thecarbon atom and any heteroatom as well as the bonds between any twoheteroatoms, may be a single or multiple covalent bond or a coordinatingor other donative bond. Thus, an alkyl group substituted with aheterocycloalkyl-, aryl-substituted heterocycloalkyl-, heteroaryl-,alkyl-substituted heteroaryl-, alkoxy-, aryloxy-, dihydrocarbylboryl-,dihydrocarbylphosphino-, dihydrocarbylamino-, trihydrocarbylsilyl-,hydrocarbylthio-, or hydrocarbylseleno-group is within the scope of theterm heteroalkyl. Examples of suitable heteroalkyl groups includecyanomethyl-, benzoylmethyl-, (2-pyridyl)methyl-, andtrifluoromethyl-groups.

As used herein the term “aromatic” refers to a polyatomic, cyclic,conjugated ring system containing (4δ+2) π-electrons, wherein δ is aninteger greater than or equal to 1. The term “fused” as used herein withrespect to a ring system containing two or more polyatomic, cyclic ringsmeans that with respect to at least two rings thereof, at least one pairof adjacent atoms is included in both rings. The term “aryl” refers to amonovalent aromatic substituent which may be a single aromatic ring ormultiple aromatic rings which are fused together, linked covalently, orlinked to a common group such as a methylene or ethylene moiety.Examples of aromatic ring(s) include phenyl, naphthyl, anthracenyl, andbiphenyl, among others.

“Substituted aryl” refers to an aryl group in which one or more hydrogenatoms bound to any carbon is replaced by one or more functional groupssuch as alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl,heterocycloalkyl, substituted heterocycloalkyl, halogen, alkylhalos (forexample, CF₃), hydroxy, amino, phosphido, alkoxy, amino, thio, nitro,and both saturated and unsaturated cyclic hydrocarbons which are fusedto the aromatic ring(s), linked covalently or linked to a common groupsuch as a methylene or ethylene moiety. The common linking group mayalso be a carbonyl as in benzophenone or oxygen as in diphenylether ornitrogen in diphenylamine.

The term, “shuttling agent” refers to a compound that is capable ofcausing polymeryl exchange between at least two different activecatalyst sites of the catalyst or catalysts included in the compositionunder the conditions of the polymerization. That is, transfer of apolymer fragment occurs both to and from one or more of the activecatalyst sites. In contrast to a shuttling agent, a “chain transferagent” causes termination of polymer chain growth and amounts to aone-time transfer of growing polymer from the catalyst to the transferagent. Preferably, the shuttling agent has an activity ratioR_(A-B)/R_(B-A) of from 0.01 and 100, more preferably from 0.1 to 10,most preferably from 0.5 to 2.0, and most highly preferably from 0.8 to1.2, wherein R_(A-B) is the rate of polymeryl transfer from catalyst Aactive site to catalyst B active site via the shuttling agent, andR_(B-A) is the rate of reverse polymeryl transfer, that is, the rate ofexchange starting from the catalyst B active site to catalyst A activesite via the shuttling agent. Desirably, the intermediate formed betweenthe shuttling agent and the polymeryl chain is sufficiently stable thatchain termination is relatively rare. Desirably, less than 90 percent,preferably less than 75 percent, more preferably less than 50 percentand most desirably less than 10 percent of shuttle-polymeryl productsare terminated prior to attaining 3 distinguishable polymer segments orblocks. Ideally, the rate of chain shuttling (defined by the timerequired to transfer a polymer chain from a catalyst site to the chainshuttling agent and then back to a catalyst site) is equivalent to orfaster than the rate of polymer termination, greater than or equal to10-, or even greater than or equal to 100 times faster than the rate ofpolymer termination. This permits polymer block formation on the sametime scale as polymer propagation.

By selecting different combinations of catalysts having differingpolymerization ability, and by pairing various shuttling agents ormixtures of agents with these catalyst combinations, polymer productshaving segments of different properties, different block lengths, anddifferent numbers of such segments or blocks in each copolymer can beprepared. For example, if the activity of the shuttling agent is lowrelative to the catalyst polymer chain propagation rate of one or moreof the catalysts, longer block length multi-block copolymers and polymerblends may be obtained. Contrariwise, if shuttling is very fast relativeto polymer chain propagation, a copolymer having a more random chainstructure and shorter block lengths is obtained. An extremely fastshuttling agent may produce a multi-block copolymer having substantiallyrandom copolymer properties. By proper selection of both catalystmixture and shuttling agent, relatively pure block copolymers,copolymers containing relatively large polymer segments or blocks,and/or blends of the foregoing with various homopolymers and/orcopolymers can be obtained. By use of the polar aprotic solventsaccording to the present invention, higher molecular weight multi-blockcopolymers having relatively longer block lengths are readilyobtainable.

Highly desirably, multi-block copolymers prepared according to thepresent invention have an average number of blocks or segments peraverage chain (as defined as the average number of blocks of differentcomposition divided by the Mn of the polymer) greater than 3.0 morepreferably greater than 3.5, even more preferably greater than 4.0, andless than 25, preferably less than 15, more preferably less than 10.0,most preferably less than 8.0 are formed according to the invention. Mwand Mn for the purposes of this invention is determined using gelpermeation chromatography (GPC) as elaborated here-in-after.

Suitable shuttling agents for use herein include Group 1, 2, 12 or 13metal compounds or complexes containing at least one C₁₋₂₀ hydrocarbylgroup, preferably hydrocarbyl substituted aluminum, gallium or zinccompounds containing from 1 to 12 carbons in each hydrocarbyl group, andreaction products thereof with a proton source. Preferred hydrocarbylgroups are alkyl groups, preferably linear or branched, C₂₋₈ alkylgroups. Most preferred shuttling agents for use in the present inventionare trialkyl aluminum compounds having from 1 to 8 carbons in each alkylgroup. Examples include: triethylaluminum, tri(i-propyl) aluminum,tri(1-butyl)aluminum, tri(n-hexyl) aluminum, tri(n-octyl)aluminum,triethyl gallium, diethyl zinc, diisobutyl zinc and dioctyl zinc.Additional suitable shuttling agents include the reaction product ormixture formed by combining the foregoing organometal compound,preferably a tri(C₁₋₈) alkyl aluminum or di(C₁₋₈) alkyl zinc compoundwith less than a stoichiometric quantity (relative to the number ofhydrocarbyl groups) of a secondary amine or a hydroxyl compound,especially bis(trimethylsilyl)amine, t-butyl(dimethyl)siloxane,2-hydroxymethylpyridine, di(n-pentyl)amine, 2,6-di(t-butyl)phenol,ethyl(1-naphthyl)amine, bis(2,3,6,7-dibenzo-1-azacycloheptaneamine), or2,6-diphenylphenol. Desirably, sufficient amine or hydroxyl reagent isused such that one hydrocarbyl group remains per metal atom. The primaryreaction products of the foregoing combinations most desired for use inthe present invention as shuttling agents are n-octylaluminumdi(bis(trimethylsilyl)amide), i-propylaluminumbis(dimethyl(t-butyl)siloxide), and n-octylaluminumdi(pyridinyl-2-methoxide), i-butylaluminumbis(dimethyl(t-butyl)siloxane), i-butylaluminumbis(di(trimethylsilyl)amide), n-octylaluminum di(pyridine-2-methoxide),i-butylaluminum bis(di(n-pentyl)amide), n-octylaluminumbis(2,6-di-t-butylphenoxide), n-octylaluminumdi(ethyl(1-naphthyl)amide), ethylaluminum bis(t-butyldimethylsiloxide),ethylaluminum di(bis(trimethylsilyl)amide), ethylaluminumbis(2,3,6,7-dibenzo-1-azacycloheptaneamide), n-octylaluminumbis(2,3,6,7-dibenzo-1-azacycloheptaneamide), n-octylaluminumbis(dimethyl(t-butyl)siloxide, ethylzinc (2,6-diphenylphenoxide), andethylzinc (t-butoxide). Especially preferred shuttling agents aretrimethyl aluminum, triethyl aluminum and tri i-propyl aluminum.

It will be appreciated by the skilled artisan that a suitable shuttlingagent for one catalyst or catalyst combination may not necessarily be asgood or even satisfactory for use with a different catalyst or catalystcombination. Some potential shuttling agents may adversely affect theperformance of one or more catalysts and may be undesirable for use forthat reason as well. Accordingly, the activity of the chain shuttlingagent desirably is balanced with the catalytic activity of the catalyststo achieve the desired polymer properties. In some embodiments of theinvention, best results may be obtained by use of shuttling agentshaving a chain shuttling activity (as measured by the average number ofblocks per number average molecular weight (Mn) of the polymer chain)that is less than is possible using more active chain shuttling agents.

Generally however, preferred shuttling agents possess the highest ratesof reversible polymer transfer as well as the highest transferefficiencies (reduced incidences of chain termination). Such shuttlingagents may be used in reduced reactor concentrations and still achievethe desired degree of shuttling. In addition, such shuttling agentsresult in production of relatively shorter polymer block lengths and/ormore blocks per average polymer chain. Highly desirably, chain shuttlingagents with a single exchange site are employed due to the fact that theeffective molecular weight of the polymer in the reactor is lowered,thereby reducing viscosity of the reaction mixture and consequentlyreducing operating costs. For the purposes of this invention, the term“single exchange site” refers to a chain shuttling agent that, duringthe chain shuttling polymerization reaction, has a single alkyl orpolymeryl group that can reversibly exchange with growing polymerylgroups on the active polymerization catalyst species. For example,diethyl zinc has two exchange sites, presumably giving dipolymerylzincspecie during the exchange process. An example of a single exchange sitechain shuttling agent would be EtZn-L, where L is a ligand that is notexchanged, yet does not prevent the reversible exchange of the remainingpolymeryl group.

Suitable catalysts for use herein include any compound or combination ofcompounds that is adapted for preparing polymers of the desiredcomposition or type. Both heterogeneous and homogeneous catalysts may beemployed. Examples of heterogeneous catalysts include the well knownZiegler-Natta compositions, especially Group 4 metal halides supportedon Group 2 metal halides or mixed halides and alkoxides and the wellknown chromium or vanadium based catalysts. Preferably however, for easeof use and for production of narrow molecular weight polymer segments insolution, the catalysts for use herein are homogeneous catalystscomprising a relatively pure organometallic compound or metal complex,especially compounds or complexes based on metals selected from Groups3-10 or the Lanthanide series of the Periodic Table of the Elements. Itis preferred that any catalyst employed herein, not significantlydetrimentally affect the performance of the other catalyst under theconditions of the present polymerization. Desirably, no catalyst isreduced in activity by greater than 25 percent, more preferably greaterthan 10 percent under the conditions of the present polymerization.

By catalyst activity reduction, it is meant that it is desirable thatthe presence of a second (or more) catalyst species in the reactor doesnot reduce the catalytic efficiency of the other catalyst species. Thiscan be determined, for example, by independently evaluating eachcatalyst species in the absence of the other(s), under the sameconditions of stirring, temperature, solvent, monomer type andconcentrations, and in the absence of chain shuttling agents. Theactivity of each catalyst as run independently of other catalysts canthen be compared to the case where the catalysts are combined in thereactor under the same conditions of stirring, temperature, solvent,monomer type and concentrations, and in the absence of chain shuttlingagents. In this case, the products of each type of catalyst species cangenerally be separated by some procedure and quantified. For example, inthe absence of a chain shuttling agent, the product resulting from theuse of two distinct catalysts often results in a bimodal molecularweight distribution, which can be evaluated using standard GPCtechniques and the amount of each component quantified using standarddeconvolution techniques which are well known in the art. If twohypothetical transition metal containing catalysts, Catalyst A andCatalyst B, were determined to have a catalyst activity of 100,000 grampolymer per gram of transition metal added to the reactor and 200,000gram polymer per gram of transition metal added to the reactorrespectively when run independently, and 100,000 g/g and 180,000 g/grespectively when run together, Catalyst A will have reduced theactivity of Catalyst B by 10 percent.

Suitable metal complexes for use herein include complexes of transitionmetals selected from Groups 3 to 15 of the Periodic Table of theElements containing one or more delocalized, n-bonded ligands or Lewisbase ligands. Examples include metallocene, half-metallocene,constrained geometry, and pyridylamine, or other monodentate ormultidentate base complexes. The complexes are generically depicted bythe formula: MK_(k)X_(x)Z_(z), or a dimer thereof, wherein

M is a metal selected from Groups 3-15, preferably 3-10, more preferably4-8, and most preferably Group 4 of the Periodic Table of the Elements;

K independently each occurrence is a group containing delocalizedπ-electrons or one or more electron pairs through which K is bound to M,said K group containing up to 50 atoms not counting hydrogen atoms,optionally two or more K groups may be joined together forming a bridgedstructure, and further optionally one or more K groups may be bound toZ, to X or to both Z and X;

X independently each occurrence is a monovalent, anionic moiety havingup to 40 non-hydrogen atoms, optionally one or more X groups may bebonded together thereby forming a divalent or polyvalent anionic group,and, further optionally, one or more X groups and one or more Z groupsmay be bonded together thereby forming a moiety that is bound to M in apolydentate fashion with formally anionic and formally neutral donoratoms;

Z independently each occurrence is a neutral, Lewis base donor ligand ofup to 50 non-hydrogen atoms containing at least one electron pairthrough which Z is coordinated to M;

k is an integer from 0 to 3;

x is an integer from 1 to 4;

z is a number from 0 to 3; and

the sum, k+x, is equal to the formal oxidation state of M.

Suitable metal complexes include those containing from 1 to 3 πL-bondedanionic or neutral ligand groups, which may be cyclic or non-cyclicdelocalized π-bonded anionic ligand groups. Exemplary of such π-bondedgroups are conjugated or nonconjugated, cyclic or non-cyclic diene anddienyl groups, allyl groups, boratabenzene groups, phosphole, and arenegroups. By the term “π-bonded” is meant that the ligand group is bondedto the transition metal by a sharing of electrons from a partiallydelocalized π-bond.

Each atom in the delocalized π-bonded group may independently besubstituted with a radical selected from the group consisting ofhydrogen, halogen, hydrocarbyl, halohydrocarbyl, hydrocarbyl-substitutedheteroatoms wherein the heteroatom is selected from Group 14-16 of thePeriodic Table of the Elements, and such hydrocarbyl-substitutedheteroatom radicals further substituted with a Group 15 or 16 heteroatom containing moiety. In addition two or more such radicals maytogether form a fused ring system, including partially or fullyhydrogenated fused ring systems, or they may form a metallocycle withthe metal. Included within the term “hydrocarbyl” are C₁₋₂₀ straight,branched and cyclic alkyl radicals, C₆₋₂₀ aromatic radicals, C₇₋₂₀alkyl-substituted aromatic radicals, and C₇₋₂₀ aryl-substituted alkylradicals. Suitable hydrocarbyl-substituted heteroatom radicals includemono-, di- and tri-substituted radicals of boron, silicon, germanium,nitrogen, phosphorus or oxygen wherein each of the hydrocarbyl groupscontains from 1 to 20 carbon atoms. Examples include N,N-dimethylamino,pyrrolidinyl, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl,methyldi(t-butyl)silyl, triphenylgermyl, and trimethylgermyl groups.Examples of Group 15 or 16 hetero atom containing moieties includeamino, phosphino, alkoxy, or alkylthio moieties or divalent derivativesthereof, for example, amide, phosphide, alkyleneoxy or alkylenethiogroups bonded to the transition metal or Lanthanide metal, and bonded tothe hydrocarbyl group, π-bonded group, or hydrocarbyl-substitutedheteroatom.

Examples of suitable anionic, delocalized π-bonded groups includecyclopentadienyl, indenyl, fluorenyl, tetrahydroindenyl,tetrahydrofluorenyl, octahydrofluorenyl, pentadienyl, cyclohexadienyl,dihydroanthracenyl, hexahydroanthracenyl, decahydroanthracenyl groups,phosphole, and boratabenzyl groups, as well as inertly substitutedderivatives thereof, especially C₁₋₁₀ hydrocarbyl-substituted ortris(C₁₋₁₀ hydrocarbyl)silyl-substituted derivatives thereof. By“inertly substituted derivative” it is meant that the substituent doesnot contain functionality that reacts with any catalyst or cocatalystcomponent or chain shuttling agent in the reaction mixture, therebyreducing catalyst or chain-shuttling activity. Preferred anionicdelocalized n-bonded groups are cyclopentadienyl,pentamethylcyclopentadienyl, tetramethylcyclopentadienyl,tetramethylsilylcyclopentadienyl, indenyl, 2,3-dimethylindenyl,fluorenyl, 2-methylindenyl, 2-methyl-4-phenylindenyl,tetrahydrofluorenyl, octahydrofluorenyl, 1-indacenyl,3-pyrrolidinoinden-1-yl, 3,4-(cyclopenta(l)phenanthren-1-yl, andtetrahydroindenyl. The boratabenzenyl ligands are anionic ligands whichare boron containing analogues to benzene. They are previously known inthe art having been described by G. Herberich, et al., inOrganometallics, 14, 1, 471-480 (1995). Preferred boratabenzenyl ligandscorrespond to the formula:

wherein R¹ is an inert substituent, preferably selected from the groupconsisting of hydrogen, hydrocarbyl, silyl, halo or germyl, said R¹having up to 20 atoms not counting hydrogen, and optionally two adjacentR¹ groups may be joined together. In complexes involving divalentderivatives of such delocalized π-bonded groups one atom thereof isbonded by means of a covalent bond or a covalently bonded divalent groupto another atom of the complex thereby forming a bridged system.

Phospholes are anionic ligands that are phosphorus containing analoguesto a cyclopentadienyl group. They are previously known in the art havingbeen described by WO 98/50392, and elsewhere. Preferred phospholeligands correspond to the formula:

wherein R¹ is as previously defined.

Preferred transition metal complexes for use herein correspond to theformula: MK_(k)X_(x)Z_(z), or a dimer thereof, wherein:

M is a Group 4 metal;

K is a group containing delocalized π-electrons through which K is boundto M, said K group containing up to 50 atoms not counting hydrogenatoms, optionally two K groups may be joined together forming a bridgedstructure, and further optionally one K may be bound to X or Z;

X independently each occurrence is a monovalent, anionic moiety havingup to 40 non-hydrogen atoms, optionally one or more X and one or more Kgroups are bonded together to form a metallocycle, and furtheroptionally one or more X and one or more Z groups are bonded togetherthereby forming a moiety that is bound to M in a polydentate fashionwith formally anionic and formally neutral donor atoms;

Z independently each occurrence is a neutral, Lewis base donor ligand ofup to 50 non-hydrogen atoms containing at least one electron pairthrough which Z is coordinated to M;

k is an integer from 0 to 3;

x is an integer from 1 to 4;

z is a number from 0 to 3; and

the sum, k+x, is equal to the formal oxidation state of M.

Preferred complexes include those containing either one or two K groups.The latter complexes include those containing a bridging group linkingthe two K groups. Preferred bridging groups are those corresponding tothe formula (ER′₂)_(e) wherein E is silicon, germanium, tin, or carbon,R′ independently each occurrence is hydrogen or a group selected fromsilyl, hydrocarbyl, hydrocarbyloxy and combinations thereof, said R′having up to 30 carbon or silicon atoms, and e is 1 to 8. Preferably, R′independently each occurrence is methyl, ethyl, propyl, benzyl,tert-butyl, phenyl, methoxy, ethoxy or phenoxy.

Examples of the complexes containing two K groups are compoundscorresponding to the formula:

wherein:

M is titanium, zirconium or hafnium, preferably zirconium or hafnium, inthe +2 or +4 formal oxidation state;

R³ in each occurrence independently is selected from the groupconsisting of hydrogen, hydrocarbyl, silyl, germyl, cyano, halo andcombinations thereof, said R³ having up to 20 non-hydrogen atoms, oradjacent R³ groups together form a divalent derivative (that is, ahydrocarbadiyl, siladiyl or germadiyl group) thereby forming a fusedring system, and

X″ independently each occurrence is an anionic ligand group of up to 40non-hydrogen atoms, or two X″ groups together form a divalent anionicligand group of up to 40 non-hydrogen atoms or together are a conjugateddiene having from 4 to 30 non-hydrogen atoms bound by means ofdelocalized π-electrons to M, whereupon M is in the +2 formal oxidationstate, and

R′, E and e are as previously defined.

Exemplary bridged ligands containing two π-bonded groups are:dimethylbis(cyclopentadienyl)silane,dimethylbis(tetramethylcyclopentadienyl)silane,dimethylbis(2-ethylcyclopentadien-1-yl)silane,dimethylbis(2-t-butylcyclopentadien-1-yl)silane,2,2-bis(tetramethylcyclopentadienyl)propane,dimethylbis(inden-1-yl)silane, dimethylbis(tetrahydroinden-1-yl)silane,dimethylbis(fluoren-1-yl)silane,dimethylbis(tetrahydrofluoren-1-yl)silane,dimethylbis(2-methyl-4-phenylinden-1-yl)-silane,dimethylbis(2-methylinden-1-yl)silane,dimethyl(cyclopentadienyl)(fluoren-1-yl)silane,dimethyl(cyclopentadienyl)(octahydrofluoren-1-yl)silane,dimethyl(cyclopentadienyl)(tetrahydrofluoren-1-yl)silane,(1,1,2,2-tetramethy)-1,2-bis(cyclopentadienyl)disilane,(1,2-bis(cyclopentadienyl)ethane, anddimethyl(cyclopentadienyl)-1-(fluoren-1-yl)methane.

Preferred X″ groups are selected from hydride, hydrocarbyl, silyl,germyl, halohydrocarbyl, halosilyl, silylhydrocarbyl andaminohydrocarbyl groups, or two X″ groups together form a divalentderivative of a conjugated diene or else together they form a neutral,π-bonded, conjugated diene. Most preferred X″ groups are C₁₋₂₀hydrocarbyl groups.

Examples of metal complexes of the foregoing formula suitable for use inthe present invention include:

-   bis(cyclopentadienyl)zirconiumdimethyl,-   bis(cyclopentadienyl)zirconium dibenzyl,-   bis(cyclopentadienyl)zirconium methyl benzyl,-   bis(cyclopentadienyl)zirconium methyl phenyl,-   bis(cyclopentadienyl)zirconiumdiphenyl,-   bis(cyclopentadienyl)titanium-allyl,-   bis(cyclopentadienyl)zirconiummethylmethoxide,-   bis(cyclopentadienyl)zirconiummethylchloride,-   bis(pentamethylcyclopentadienyl)zirconiumdimethyl,-   bis(pentamethylcyclopentadienyl)titaniumdimethyl,-   bis(indenyl)zirconiumdimethyl,-   indenylfluorenylzirconiumdimethyl,-   bis(indenyl)zirconiummethyl(2-(dimethylamino)benzyl),-   bis(indenyl)zirconiummethyltrimethylsilyl,-   bis(tetrahydroindenyl)zirconiummethyltrimethylsilyl,-   bis(pentamethylcyclopentadienyl)zirconiummethylbenzyl,-   bis(pentamethylcyclopentadienyl)zirconiumdibenzyl,-   bis(pentamethylcyclopentadienyl)zirconiummethylmethoxide,-   bis(pentamethylcyclopentadienyl)zirconiummethylchloride,-   bis(methylethylcyclopentadienyl)zirconiumdimethyl,-   bis(butylcyclopentadienyl)zirconiumdibenzyl,-   bis(t-butylcyclopentadienyl)zirconiumdimethyl,-   bis(ethyltetramethylcyclopentadienyl)zirconiumdimethyl,-   bis(methylpropylcyclopentadienyl)zirconiumdibenzyl,-   bis(trimethylsilylcyclopentadienyl)zirconiumdibenzyl,-   dimethylsilylbis(cyclopentadienyl)zirconiumdichloride,-   dimethylsilylbis(cyclopentadienyl)zirconiumdimethyl,-   dimethylsilylbis(tetramethylcyclopentadienyl)titanium (III) allyl-   dimethylsilylbis(t-butylcyclopentadienyl)zirconiumdichloride,-   dimethylsilylbis(n-butylcyclopentadienyl)zirconiumdichloride,-   (dimethylsilylbis(tetramethylcyclopentadienyl)titanium(III)    2-(dimethylamino)benzyl,-   (dimethylsilylbis(n-butylcyclopentadienyl)titanium(III)    2-(dimethylamino)benzyl,-   dimethylsilylbis(indenyl)zirconiumdichloride,-   dimethylsilylbis(indenyl)zirconiumdimethyl,-   dimethylsilylbis(2-methylindenyl)zirconiumdimethyl,-   dimethylsilylbis(2-methyl-4-phenylindenyl)zirconiumdimethyl,-   dimethylsilylbis(2-methylindenyl)zirconium-1,4-diphenyl-1,3-butadiene,-   dimethylsilylbis(2-methyl-4-phenylindenyl)zirconium (II)    1,4-diphenyl-1,3-butadiene,-   dimethylsilylbis(4,5,6,7-tetrahydroinden-1-yl)zirconiumdichloride,-   dimethylsilylbis(4,5,6,7-tetrahydroinden-1-yl)zirconiumdimethyl,-   dimethylsilylbis(tetrahydroindenyl)zirconium(II)    1,4-diphenyl-1,3-butadiene,-   dimethylsilylbis(tetramethylcyclopentadienyl)zirconium dimethyl-   dimethylsilylbis(fluorenyl)zirconiumdimethyl,-   dimethylsilylbis(tetrahydrofluorenyl)zirconium bis(trimethylsilyl),-   ethylenebis(indenyl)zirconiumdichloride,-   ethylenebis(indenyl)zirconiumdimethyl,-   ethylenebis(4,5,6,7-tetrahydroindenyl)zirconiumdichloride,-   ethylenebis(4,5,6,7-tetrahydroindenyl)zirconiumdimethyl,-   (isopropylidene)(cyclopentadienyl)(fluorenyl)zirconiumdibenzyl, and-   dimethylsilyl(tetramethylcyclopentadienyl)(fluorenyl)zirconium    dimethyl.

A further class of metal complexes utilized in the present inventioncorresponds to the preceding formula: MK_(k)Z_(z)X_(x), or a dimerthereof, wherein M, K, X, x and z are as previously defined, k is one,and Z is a substituent of up to 50 non-hydrogen atoms that together withK forms a metallocycle with M.

Preferred Z substituents include groups containing up to 30 non-hydrogenatoms comprising at least one atom that is oxygen, sulfur, boron or amember of Group 14 of the Periodic Table of the Elements directlyattached to K, and a different atom, selected from the group consistingof nitrogen, phosphorus, oxygen or sulfur that is covalently bonded toM.

More specifically this class of Group 4 metal complexes used accordingto the present invention includes “constrained geometry catalysts”corresponding to the formula:

wherein:

M is titanium or zirconium, preferably titanium in the +2, +3, or +4formal oxidation state;

K¹ is a delocalized, n-bonded ligand group optionally substituted withfrom 1 to 5 R² groups,

R² in each occurrence independently is selected from the groupconsisting of hydrogen, hydrocarbyl, silyl, germyl, cyano, halo andcombinations thereof, said R² having up to 20 non-hydrogen atoms, oradjacent R² groups together form a divalent derivative (that is, ahydrocarbadiyl, siladiyl or germadiyl group) thereby forming a fusedring system,

each X is independently a halo, hydride, hydrocarbyl, hydrocarbyloxy orsilyl group, said group having up to 20 non-hydrogen atoms, or two Xgroups together form a neutral C₅₋₃₀ conjugated diene or a divalentderivative thereof;

x is 1 or 2;

Y is —O—, —S—, —NR′—, —PR′—; and

X′ is SiR′₂, CR′₂, SiR′₂SiR′₂, CR′₂CR′₂, CR′═CR′, CR′₂SiR′₂, or GeR′₂,wherein

R′ independently each occurrence is hydrogen or a group selected fromsilyl, hydrocarbyl, hydrocarbyloxy and combinations thereof, said R′having up to 30 carbon or silicon atoms.

Specific examples of the foregoing constrained geometry metal complexesinclude compounds corresponding to the formula:

wherein,

Ar is an aryl group of from 6 to 30 atoms not counting hydrogen;

R⁴ independently each occurrence is hydrogen, Ar, or a group other thanAr selected from hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylgermyl,halide, hydrocarbyloxy, trihydrocarbylsiloxy,bis(trihydrocarbylsilyl)amino, di(hydrocarbyl)amino,hydrocarbadiylamino, hydrocarbylimino, di(hydrocarbyl)phosphino,hydrocarbadiylphosphino, hydrocarbylsulfido, halo-substitutedhydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl,trihydrocarbylsilyl-substituted hydrocarbyl,trihydrocarbylsiloxy-substituted hydrocarbyl,bis(trihydrocarbylsilyl)amino-substituted hydrocarbyl,di(hydrocarbyl)amino-substituted hydrocarbyl,hydrocarbyleneamino-substituted hydrocarbyl,di(hydrocarbyl)phosphino-substituted hydrocarbyl,hydrocarbylenephosphino-substituted hydrocarbyl, orhydrocarbylsulfido-substituted hydrocarbyl, said R group having up to 40atoms not counting hydrogen atoms, and optionally two adjacent R⁴ groupsmay be joined together forming a polycyclic fused ring group;

M is titanium;

X′ is SiR⁶ ₂, CR⁶ ₂, SiR⁶ ₂SiR⁶ ₂, CR⁶ ₂CR⁶ ₂, CR⁶═CR⁶, CR⁶ ₂SiR⁶ ₂,BR⁶, BR⁶L″, or GeR⁶ ₂;

Y is —O—, —S—, —NR⁵—, —PR⁵—; —NR⁵ ₂, or —PR⁵ ₂;

R⁵, independently each occurrence, is hydrocarbyl, trihydrocarbylsilyl,or trihydrocarbylsilylhydrocarbyl, said R⁵ having up to 20 atoms otherthan hydrogen, and optionally two R⁵ groups or R⁵ together with Y or Zform a ring system;

R⁶, independently each occurrence, is hydrogen, or a member selectedfrom hydrocarbyl, hydrocarbyloxy, silyl, halogenated alkyl, halogenatedaryl, —NR⁵ ₂, and combinations thereof, said R⁶ having up to 20non-hydrogen atoms, and optionally, two R⁶ groups or R⁶ together with Zforms a ring system;

Z is a neutral diene or a monodentate or polydentate Lewis baseoptionally bonded to R⁵, R⁶, or X;

X is hydrogen, a monovalent anionic ligand group having up to 60 atomsnot counting hydrogen, or two X groups are joined together therebyforming a divalent ligand group;

x is 1 or 2; and

z is 0, 1 or 2.

Preferred examples of the foregoing metal complexes are substituted atboth the 3- and 4-positions of a cyclopentadienyl or indenyl group withan Ar group.

Examples of the foregoing metal complexes include:

-   (3-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,3-diphenyl-1,3-butadiene;-   (3-(pyrrol-1-yl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-(pyrrol-1-yl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-(pyrrol-1-yl)cyclopentadien-1-yl))dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (3-(1-methylpyrrol-3-yl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-(1-methylpyrrol-3-yl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-(1-methylpyrrol-3-yl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (3,4-diphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3,4-diphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3,4-diphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,3-pentadiene;-   (3-(3-N,N-dimethylamino)phenyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-(3-N,N-dimethylamino)phenylcyclopentadien-1-yl)dimethyl(t-butylamido)    silanetitanium dimethyl,-   (3-(3-N,N-dimethylamino)phenylcyclopentadien-1-yl)dimethyl(t-butylamido)    silanetitanium (II) 1,4-diphenyl-1,3-butadiene;-   (3-(4-methoxyphenyl)-4-methylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-(4-methoxyphenyl)-4-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-4-methoxyphenyl)-4-phenylcyclopentadien-1-yl)dimethyl(t-butylamido)    silanetitanium (II) 1,4-diphenyl-1,3-butadiene;-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (3-phenyl-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)    silanetitanium dichloride,-   (3-phenyl-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)    silanetitanium dimethyl,-   (3-phenyl-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   2-methyl-(3,4-di(4-methylphenyl)cyclopentadien-1-yl)dimethyl(t-butylamido)    silanetitanium dichloride,-   2-methyl-(3,4-di(4-methylphenyl)cyclopentadien-1-yl)dimethyl(t-butylamido)    silanetitanium dimethyl,-   2-methyl-(3,4-di(4-methylphenyl)cyclopentadien-1-yl)dimethyl(t-butylamido)    silanetitanium (II) 1,4-diphenyl-1,3-butadiene;-   ((2,3-diphenyl)-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)    silane titanium dichloride,-   ((2,3-diphenyl)-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)silane    titanium dimethyl,-   ((2,3-diphenyl)-4-(N,N-dimethylamino)cyclopentadien-1-yl)dimethyl(t-butylamido)    silanetitanium (II) 1,4-diphenyl-1,3-butadiene;-   (2,3,4-triphenyl-5-methylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (2,3,4-triphenyl-5-methylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (2,3,4-triphenyl-5-methylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (3-phenyl-4-methoxycyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (2,3-diphenyl-4-(n-butyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (2,3-diphenyl-4-(n-butyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl,-   (2,3-diphenyl-4-(n-butyl)cyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene;-   (2,3,4,5-tetraphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dichloride,-   (2,3,4,5-tetraphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium    dimethyl, and-   (2,3,4,5-tetraphenylcyclopentadien-1-yl)dimethyl(t-butylamido)silanetitanium (II)    1,4-diphenyl-1,3-butadiene.

Additional examples of suitable metal complexes for use herein arepolycyclic complexes corresponding to the formula:

where M is titanium in the +2, +3 or +4 formal oxidation state;

R⁷ independently each occurrence is hydride, hydrocarbyl, silyl, germyl,halide, hydrocarbyloxy, hydrocarbylsiloxy, hydrocarbylsilylamino,di(hydrocarbyl)amino, hydrocarbyleneamino, di(hydrocarbyl)phosphino,hydrocarbylene-phosphino, hydrocarbylsulfido, halo-substitutedhydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, silyl-substitutedhydrocarbyl, hydrocarbylsiloxy-substituted hydrocarbyl,hydrocarbylsilylamino-substituted hydrocarbyl,di(hydrocarbyl)amino-substituted hydrocarbyl,hydrocarbyleneamino-substituted hydrocarbyl,di(hydrocarbyl)phosphino-substituted hydrocarbyl,hydrocarbylene-phosphino-substituted hydrocarbyl, orhydrocarbylsulfido-substituted hydrocarbyl, said R⁷ group having up to40 atoms not counting hydrogen, and optionally two or more of theforegoing groups may together form a divalent derivative;

R⁸ is a divalent hydrocarbylene- or substituted hydrocarbylene groupforming a fused system with the remainder of the metal complex, said R⁸containing from 1 to 30 atoms not counting hydrogen;

X^(a) is a divalent moiety, or a moiety comprising one σ-bond and aneutral two electron pair able to form a coordinate-covalent bond to M,said X^(a) comprising boron, or a member of Group 14 of the PeriodicTable of the Elements, and also comprising nitrogen, phosphorus, sulfuror oxygen;

X is a monovalent anionic ligand group having up to 60 atoms exclusiveof the class of ligands that are cyclic, delocalized, π-bound ligandgroups and optionally two X groups together form a divalent ligandgroup;

Z independently each occurrence is a neutral ligating compound having upto 20 atoms;

x is 0, 1 or 2; and

z is zero or 1.

Preferred examples of such complexes are 3-phenyl-substituteds-indecenyl complexes corresponding to the formula:

2,3-dimethyl-substituted s-indecenyl complexes corresponding to theformulas:

or 2-methyl-substituted s-indecenyl complexes corresponding to theformula:

Additional examples of metal complexes that are usefully employedaccording to the present invention include those of the formula:

Specific metal complexes include:

-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,4-diphenyl-1,3-butadiene,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,3-pentadiene,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (III) 2-(N,N-dimethylamino)benzyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dichloride,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dimethyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dibenzyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,4-diphenyl-1,3-butadiene,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,3-pentadiene,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (III) 2-(N,N-dimethylamino)benzyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dichloride,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dimethyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-1-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dibenzyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,4-diphenyl-1,3-butadiene,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,3-pentadiene,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (III) 2-(N,N-dimethylamino)benzyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dichloride,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dimethyl,-   (8-methylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dibenzyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,4-diphenyl-1,3-butadiene,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (II) 1,3-pentadiene,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (III) 2-(N,N-dimethylamino)benzyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dichloride,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dimethyl,-   (8-difluoromethylene-1,8-dihydrodibenzo[e,h]azulen-2-yl)-N-(1,1-dimethylethyl)dimethylsilanamide    titanium (IV) dibenzyl, and mixtures thereof, especially mixtures of    positional isomers.

Further illustrative examples of metal complexes for use according tothe present invention correspond to the formula:

where M is titanium in the +2, +3 or +4 formal oxidation state;

T is —NR⁹— or —O—;

R⁹ is hydrocarbyl, silyl, germyl, dihydrocarbylboryl, or halohydrocarbylor up to 10 atoms not counting hydrogen;

R¹⁰ independently each occurrence is hydrogen, hydrocarbyl,trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl, germyl, halide,hydrocarbyloxy, hydrocarbylsiloxy, hydrocarbylsilylamino,di(hydrocarbyl)amino, hydrocarbyleneamino, di(hydrocarbyl)phosphino,hydrocarbylene-phosphino, hydrocarbylsulfido, halo-substitutedhydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, silyl-substitutedhydrocarbyl, hydrocarbylsiloxy-substituted hydrocarbyl,hydrocarbylsilylamino-substituted hydrocarbyl,di(hydrocarbyl)amino-substituted hydrocarbyl,hydrocarbyleneamino-substituted hydrocarbyl,di(hydrocarbyl)phosphino-substituted hydrocarbyl,hydrocarbylenephosphino-substituted hydrocarbyl, orhydrocarbylsulfido-substituted hydrocarbyl, said R¹⁰ group having up to40 atoms not counting hydrogen atoms, and optionally two or more of theforegoing adjacent R¹⁰ groups may together form a divalent derivativethereby forming a saturated or unsaturated fused ring;

X^(a) is a divalent moiety lacking in delocalized π-electrons, or such amoiety comprising one σ-bond and a neutral two electron pair able toform a coordinate-covalent bond to M, said X′ comprising boron, or amember of Group 14 of the Periodic Table of the Elements, and alsocomprising nitrogen, phosphorus, sulfur or oxygen;

X is a monovalent anionic ligand group having up to 60 atoms exclusiveof the class of ligands that are cyclic ligand groups bound to M throughdelocalized π-electrons or two X groups together are a divalent anionicligand group;

Z independently each occurrence is a neutral ligating compound having upto 20 atoms;

x is 0, 1, 2, or 3; and

z is 0 or 1.

Highly preferably T is ═N(CH₃), X is halo or hydrocarbyl, x is 2, X′ isdimethylsilane, z is 0, and R¹⁰ each occurrence is hydrogen, ahydrocarbyl, hydrocarbyloxy, dihydrocarbylamino, hydrocarbyleneamino,dihydrocarbylamino-substituted hydrocarbyl group, orhydrocarbyleneamino-substituted hydrocarbyl group of up to 20 atoms notcounting hydrogen, and optionally two R¹⁰ groups may be joined together.

Illustrative metal complexes of the foregoing formula that may beemployed in the practice of the present invention further include thefollowing compounds:

-   (t-butylamido)dimethyl-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (t-butylamido)dimethyl-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,3-pentadiene,-   (t-butylamido)dimethyl-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (III)    2-(N,N-dimethylamino)benzyl,-   (t-butylamido)dimethyl-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dichloride,-   (t-butylamido)dimethyl-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dimethyl,-   (t-butylamido)dimethyl-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dibenzyl,-   (t-butylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    bis(trimethylsilyl),-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,3-pentadiene,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (III)    2-(N,N-dimethylamino)benzyl,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dichloride,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dimethyl,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dibenzyl,-   (cyclohexylamido)dimethyl-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    bis(trimethylsilyl),-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,3-pentadiene,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (III)    2-(N,N-dimethylamino)benzyl,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dichloride,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dimethyl,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dibenzyl,-   (t-butylamido)di(p-methylphenyl)-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    bis(trimethylsilyl),-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (cyclohexylamido)di(p-methylphenyl)-[6,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (II)    1,3-pentadiene,-   (cyclohexylamido)di(p-methylphenyl)-[6 ,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (III)    2-(N,N-dimethylamino)benzyl,-   (cyclohexylamido)di(p-methylphenyl)-[6 ,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dichloride,-   (cyclohexylamido)di(p-methylphenyl)-[6 ,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dimethyl,-   (cyclohexylamido)di(p-methylphenyl)-[6 ,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    dibenzyl; and-   (cyclohexylamido)di(p-methylphenyl)-[6 ,7]benzo-[4,    5:2′,3′](1-methylisoindol)-(3H)-indene-2-yl)silanetitanium (IV)    bis(trimethylsilyl).

Illustrative Group 4 metal complexes that may be employed in thepractice of the present invention further include:

-   (tert-butylamido)(1,1-dimethyl-2,3,4,9,10-η-1,4,5,6,7,8-hexahydronaphthalenyl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(1,1,2,3-tetramethyl-2,3,4,9,10-η-1,4,5,6,7,8-hexahydronaphthalenyl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)    dimethylsilanetitanium dibenzyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium    dimethyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyltitanium    dimethyl,-   (tert-butylamido)(tetramethyl-η⁵-indenyl)dimethylsilanetitanium    dimethyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilane    titanium (III) 2-(dimethylamino)benzyl;-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (III)    allyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (III)    2,4-dimethylpentadienyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (II)    1,3-pentadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (II)    2,4-hexadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    2,3-dimethyl-1,3-butadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    isoprene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    1,3-butadiene,-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    2,3-dimethyl-1,3-butadiene,-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    isoprene-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    dimethyl-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    dibenzyl-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (IV)    1,3-butadiene,-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (II)    1,3-pentadiene,-   (tert-butylamido)(2,3-dimethylindenyl)dimethylsilanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (II)    1,3-pentadiene,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    dimethyl,-   (tert-butylamido)(2-methylindenyl)dimethylsilanetitanium (IV)    dibenzyl,-   (tert-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitanium (II)    1,4-diphenyl-1,3-butadiene,-   (tert-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitanium (II)    1,3-pentadiene,-   (tert-butylamido)(2-methyl-4-phenylindenyl)dimethylsilanetitanium (II)    2,4-hexadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethyl-silanetitanium (IV)    1,3-butadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (IV)    2,3-dimethyl-1,3-butadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (IV)    isoprene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethyl-silanetitanium (II)    1,4-dibenzyl-1,3-butadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilanetitanium (II)    2,4-hexadiene,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethyl-silanetitanium (II)    3-methyl-1,3-pentadiene,-   (tert-butylamido)(2,4-dimethylpentadien-3-yl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(6,6-dimethylcyclohexadienyl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(1,1-dimethyl-2,3,4,9,10-η-1,4,5,6,7,8-hexahydronaphthalen-4-yl)dimethylsilanetitaniumdimethyl,-   (tert-butylamido)(1,1,2,3-tetramethyl-2,3,4,9,10-η-1,4,5,6,7,8-hexahydronaphthalen-4-yl)dimethylsilanetitaniumdimethyl-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl    methylphenylsilanetitanium (IV) dimethyl,-   (tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl    methylphenylsilanetitanium (II) 1,4-diphenyl-1,3-butadiene,-   1-(tert-butylamido)-2-(tetramethyl-η⁵-cyclopentadienyl)ethanediyltitanium (IV)    dimethyl, and-   1-(tert-butylamido)-2-(tetramethyl-η⁵-cyclopentadienyl)ethanediyl-titanium (II)    1,4-diphenyl-1,3-butadiene.

Other delocalized, n-bonded complexes, especially those containing otherGroup 4 metals, will, of course, be apparent to those skilled in theart, and are disclosed among other places in: WO 03/78480, WO 03/78483,WO 02/92610, WO 02/02577, US 2003/0004286 and U.S. Pat. Nos. 6,515,155,6,555,634, 6,150,297, 6,034,022, 6,268,444, 6,015,868, 5,866,704, and5,470,993.

Additional examples of metal complexes that are usefully employed ascatalysts in the present invention are complexes of polyvalent Lewisbases corresponding to the formula:

preferably

wherein T^(b) is a bridging group, preferably containing 2 or more atomsother than hydrogen,

X^(b) and Y^(b) are each independently selected from the groupconsisting of nitrogen, sulfur, oxygen and phosphorus; more preferablyboth X^(b) and Y^(b) are nitrogen,

R^(b) and R^(b′) independently each occurrence are hydrogen or C₁₋₅₀hydrocarbyl groups optionally containing one or more heteroatoms orinertly substituted derivative thereof. Non-limiting examples ofsuitable R^(b) and R^(b′) groups include alkyl, alkenyl, aryl, aralkyl,(poly)alkylaryl and cycloalkyl groups, as well as nitrogen, phosphorus,oxygen and halogen substituted derivatives thereof. Specific examples ofsuitable R^(b) and R^(b′) groups include methyl, ethyl, isopropyl,octyl, phenyl, 2,6-dimethylphenyl, 2,6-di(isopropyl)phenyl,2,4,6-trimethylphenyl, pentafluorophenyl, 3,5-trifluoromethylphenyl, andbenzyl;

g is 0 or 1;

M^(b) is a metallic element selected from Groups 3 to 15, or theLanthanide series of the Periodic Table of the Elements. Preferably,M^(b) is a Group 3-13 metal, more preferably M^(b) is a Group 4-10metal;

L^(b) is a monovalent, divalent, or trivalent anionic ligand containingfrom 1 to 50 atoms, not counting hydrogen. Examples of suitable L^(b)groups include halide; hydride; hydrocarbyl, hydrocarbyloxy;di(hydrocarbyl)amido, hydrocarbyleneamido, di(hydrocarbyl)phosphido;hydrocarbylsulfido; hydrocarbyloxy, tri(hydrocarbylsilyl)alkyl; andcarboxylates. More preferred L^(b) groups are C₁₋₂₀ alkyl, C₇₋₂₀aralkyl, and chloride;

h is an integer from 1 to 6, preferably from 1 to 4, more preferablyfrom 1 to 3, and j is 1 or 2, with the value h×j selected to providecharge balance;

Z^(b) is a neutral ligand group coordinated to M^(b), and containing upto 50 atoms not counting hydrogen Preferred Z^(b) groups includealiphatic and aromatic amines, phosphines, and ethers, alkenes,alkadienes, and inertly substituted derivatives thereof. Suitable inertsubstituents include halogen, alkoxy, aryloxy, alkoxycarbonyl,aryloxycarbonyl, di(hydrocarbyl)amine, tri(hydrocarbyl)silyl, andnitrile groups. Preferred Z^(b) groups include triphenylphosphine,tetrahydrofuran, pyridine, and 1,4-diphenylbutadiene;

f is an integer from 1 to 3;

two or three of T^(b), R^(b) and R^(b′) may be joined together to form asingle or multiple ring structure;

h is an integer from 1 to 6, preferably from 1 to 4, more preferablyfrom 1 to 3;

indicates any form of electronic interaction, especially coordinate orcovalent bonds, including multiple bonds, arrows signify coordinatebonds, and dotted lines indicate optional double bonds.

In one embodiment, it is preferred that R^(b) have relatively low sterichindrance with respect to X^(b). In this embodiment, most preferredR^(b) groups are straight chain alkyl groups, straight chain alkenylgroups, branched chain alkyl groups wherein the closest branching pointis at least 3 atoms removed from X^(b), and halo, dihydrocarbylamino,alkoxy or trihydrocarbylsilyl substituted derivatives thereof. Highlypreferred R^(b) groups in this embodiment are C₁₋₈ straight chain alkylgroups.

At the same time, in this embodiment R^(b′) preferably has relativelyhigh steric hindrance with respect to Y^(b). Non-limiting examples ofsuitable R^(b′) groups for this embodiment include alkyl or alkenylgroups containing one or more secondary or tertiary carbon centers,cycloalkyl, aryl, alkaryl, aliphatic or aromatic heterocyclic groups,organic or inorganic oligomeric, polymeric or cyclic groups, and halo,dihydrocarbylamino, alkoxy or trihydrocarbylsilyl substitutedderivatives thereof. Preferred R^(b′) groups in this embodiment containfrom 3 to 40, more preferably from 3 to 30, and most preferably from 4to 20 atoms not counting hydrogen and are branched or cyclic.

Examples of preferred T^(b) groups are structures corresponding to thefollowing formulas:

wherein

Each R^(d) is C₁₋₁₀ hydrocarbyl group, preferably methyl, ethyl,n-propyl, i-propyl, t-butyl, phenyl, 2,6-dimethylphenyl, benzyl, ortolyl. Each R^(e) is C₁₋₁₀ hydrocarbyl, preferably methyl, ethyl,n-propyl, i-propyl, t-butyl, phenyl, 2,6-dimethylphenyl, benzyl, ortolyl. In addition, two or more Rd or R^(e) groups, or mixtures of R^(d)and R^(e) groups may together form a polyvalent derivative of ahydrocarbyl group, such as, 1,4-butylene, 1,5-pentylene, or amulticyclic, fused ring, polyvalent hydrocarbyl- or heterohydrocarbyl-group, such as naphthalene-1,8-diyl.

Preferred examples of the foregoing polyvalent Lewis base complexesinclude:

wherein R^(d′) each occurrence is independently selected from the groupconsisting of hydrogen and C₁₋₅₀ hydrocarbyl groups optionallycontaining one or more heteroatoms, or inertly substituted derivativethereof, or further optionally, two adjacent R^(d′) groups may togetherform a divalent bridging group;

d′ is 4;

M^(b′) is a Group 4 metal, preferably titanium or hafnium, or a Group 10metal, preferably Ni or Pd;

L^(b′) is a monovalent ligand of up to 50 atoms not counting hydrogen,preferably halide or hydrocarbyl, or two L^(b′) groups together are adivalent or neutral ligand group, preferably a C₂₋₅₀ hydrocarbylene,hydrocarbadiyl or diene group.

The polyvalent Lewis base complexes for use in the present inventioninclude Group 4 metal derivatives, especially hafnium derivatives, ofhydrocarbylamine substituted heteroaryl compounds, said complexescorresponding to the formula:

wherein:

R¹¹ is selected from alkyl, cycloalkyl, heteroalkyl, cycloheteroalkyl,aryl, and inertly substituted derivatives thereof containing from 1 to30 atoms not counting hydrogen or a divalent derivative thereof;

T¹ is a divalent bridging group of from 1 to 41 atoms other thanhydrogen, preferably 1 to 20 atoms other than hydrogen, and mostpreferably a mono- or di-C₁₋₂₀ hydrocarbyl substituted methylene orsilane group; and

R¹² is a C₅₋₂₀ heteroaryl group containing Lewis base functionality,especially a pyridin-2-yl- or substituted pyridin-2-yl group or adivalent derivative thereof;

M¹ is a Group 4 metal, preferably hafnium;

X¹ is an anionic, neutral or dianionic ligand group;

x′ is a number from 0 to 5 indicating the number of such X¹ groups; and

bonds, optional bonds and electron donative interactions are representedby lines, dotted lines and arrows respectively.

Preferred complexes are those wherein ligand formation results fromhydrogen elimination from the amine group and optionally from the lossof one or more additional groups, especially from R¹². In addition,electron donation from the Lewis base functionality, preferably anelectron pair, provides additional stability to the metal center.Preferred metal complexes correspond to the formula:

wherein

M¹, X¹, x′, R¹¹ and T¹ are as previously defined,

R¹³, R¹⁴, R¹⁵ and R¹⁶ are hydrogen, halo, or an alkyl, cycloalkyl,heteroalkyl, heterocycloalkyl, aryl, or silyl group of up to 20 atomsnot counting hydrogen, or adjacent R¹³, R¹⁴, R¹⁵ or R¹⁶ groups may bejoined together thereby forming fused ring derivatives, and

bonds, optional bonds and electron pair donative interactions arerepresented by lines, dotted lines and arrows respectively.

More preferred examples of the foregoing metal complexes correspond tothe formula:

wherein

M¹, X¹, and x′ are as previously defined,

R¹³, R¹⁴, R¹⁵ and R¹⁶ are as previously defined, preferably R¹³, R¹⁴,and R¹⁵ are hydrogen, or C₁₋₄ alkyl, and R¹⁶ is C₆₋₂₀ aryl, mostpreferably naphthalenyl;

R^(a) independently each occurrence is C₁₋₄ alkyl, and a is 1-5, mostpreferably R^(a) in two ortho-positions to the nitrogen is isopropyl ort-butyl;

R¹⁷ and R¹⁸ independently each occurrence are hydrogen, halogen, or aC₁₋₂₀ alkyl or aryl group, most preferably one of R¹⁷ and R¹⁸ ishydrogen and the other is a C₆₋₂₀ aryl group, especially 2-isopropyl,phenyl or a fused polycyclic aryl group, most preferably an anthracenylgroup, and covalent bonds, optional bonds and electron pair donativeinteractions are represented by lines, dotted lines and arrowsrespectively.

Highly preferred metal complexes for use herein as one of the catalystsherein correspond to the formula:

wherein X¹ each occurrence is halide, N,N-dimethylamido, or C₁₋₄ alkyl,and preferably each occurrence X¹ is methyl;

R^(f) independently each occurrence is hydrogen, halogen, C₁₋₂₀ alkyl,or C₆₋₂₀ aryl, or two adjacent R^(f) groups are joined together therebyforming a ring, and f is 1-5; and

R^(c) independently each occurrence is hydrogen, halogen, C₁₋₂₀ alkyl,or C₆₋₂₀ aryl, or two adjacent R^(c) groups are joined together therebyforming a ring, and c is 1-5.

Additional examples of metal complexes for use according to the presentinvention are complexes of the following formulas:

wherein R^(x) is C₁₋₄ alkyl or cycloalkyl, preferably methyl, isopropyl,t-butyl or cyclohexyl; and

X¹ each occurrence is halide, N,N-dimethylamido, or C₁₋₄ alkyl,preferably methyl.

Examples of metal complexes of the foregoing type include:

-   [N-(2,6-di(1-methylethyl)phenyl)amido)(o-tolyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dimethyl;-   [N-(2,6-di(1-methylethyl)phenyl)amido)(o-tolyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    di(N,N-dimethylamido);-   [N-(2,6-di(1-methylethyl)phenyl)amido)(o-tolyl)    (α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium dichloride;-   [N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dimethyl;-   [N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    di(N,N-dimethylamido);-   [N-(2,6-di(1-methylethyl)phenyl)amido)(2-isopropylphenyl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dichloride;-   [N-(2,6-di(1-methylethyl)phenyl)amido)(phenanthren-5-yl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dimethyl;-   [N-(2,6-di(1-methylethyl)phenyl)amido)(phenanthren-5-yl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    di(N,N-dimethylamido); and-   [N-(2,6-di(1-methylethyl)phenyl)amido)(phenanthren-5-yl)(α-naphthalen-2-diyl(6-pyridin-2-diyl)methane)]hafnium    dichloride.

Under the reaction conditions used to prepare the metal complexes usedin the present invention, the hydrogen of the 2-position of theα-naphthalene group substituted at the 6-position of the pyridin-2-ylgroup is subject to elimination, thereby uniquely forming metalcomplexes wherein the metal is covalently bonded to both the resultingamide group and to the 2-position of the α-naphthalenyl group, as wellas stabilized by coordination to the pyridinyl nitrogen atom through theelectron pair of the nitrogen atom.

Additional suitable metal complexes include compounds corresponding tothe formula:

where:

R²⁰ is an aromatic or inertly substituted aromatic group containing from5 to 20 atoms not counting hydrogen, or a polyvalent derivative thereof;

T³ is a hydrocarbylene or silane group having from 1 to 20 atoms notcounting hydrogen, or an inertly substituted derivative thereof;

M³ is a Group 4 metal, preferably zirconium or hafnium;

G is an anionic, neutral or dianionic ligand group; preferably a halide,hydrocarbyl or dihydrocarbylamide group having up to 20 atoms notcounting hydrogen;

g is a number from 1 to 5 indicating the number of such G groups; and

bonds and electron donative interactions are represented by lines andarrows respectively.

Preferably, such complexes correspond to the formula:

wherein:

T³ is a divalent bridging group of from 2 to 20 atoms not countinghydrogen, preferably a substituted or unsubstituted, C₃₋₆ alkylenegroup; and

Ar² independently each occurrence is an arylene or an alkyl- oraryl-substituted arylene group of from 6 to 20 atoms not countinghydrogen;

M³ is a Group 4 metal, preferably hafnium or zirconium;

G independently each occurrence is an anionic, neutral or dianionicligand group;

g is a number from 1 to 5 indicating the number of such X groups; and

electron donative interactions are represented by arrows.

Preferred examples of metal complexes of foregoing formula include thefollowing compounds:

where M³ is Hf or Zr;

Ar⁴ is C₆₋₂₀ aryl or inertly substituted derivatives thereof, especially3,5-di(isopropyl)phenyl, 3,5-di(isobutyl)phenyl, 3,5-di(t-butyl)phenyl,dibenzo-1H-pyrrole-1-yl, or anthracen-5-yl, and

T⁴ independently each occurrence comprises a C₃₋₆ alkylene group, a C₃₋₆cycloalkylene group, or an inertly substituted derivative thereof;

R²¹ independently each occurrence is hydrogen, halo, hydrocarbyl,trihydrocarbylsilyl, or trihydrocarbylsilylhydrocarbyl of up to 50 atomsnot counting hydrogen; and

G, independently each occurrence is halo or a hydrocarbyl ortrihydrocarbylsilyl group of up to 20 atoms not counting hydrogen, or 2G groups together are a divalent derivative of the foregoing hydrocarbylor trihydrocarbylsilyl groups.

Especially preferred are compounds of the formula:

wherein Ar⁴ is 3,5-di(isopropyl)phenyl, 3,5-di(isobutyl)phenyl,3,5-di(t-butyl)phenyl, dibenzo-1H-pyrrole-1-yl, or anthracen-5-yl,

R²¹ is hydrogen, halo, or C₁₋₄ alkyl, especially methyl or t-butyl

R²¹ is hydrogen, halo, or C₁₋₄ alkyl, especially methyl

T⁴ is propan-1,3-diyl, butan-1,4-diyl, cyclohexyl,dimethylene(cyclohexan-1,2-diyl), dimethylene(cyclohex-3-en-1,2-diyl),and

G is chloro, methyl or benzyl.

Other suitable metal complexes are those of the formula:

The foregoing polyvalent Lewis base complexes are conveniently preparedby standard metallation and ligand exchange procedures involving asource of the Group 4 metal and the neutral polyfunctional ligandsource. In addition, the complexes may also be prepared by means of anamide elimination and hydrocarbylation process starting from thecorresponding Group 4 metal tetraamide and a hydrocarbylating agent,such as trimethylaluminum. Other techniques may be used as well. Thesecomplexes are known from the disclosures of, among others, U.S. Pat.Nos. 6,320,005, 6,103,657, WO 02/38628, WO 03/40195, and U.S. Ser. No.04/0220050.

Additional suitable metal complexes include Group 4-10 metal derivativescorresponding to the formula:

wherein

M² is a metal of Groups 4-10 of the Periodic Table of the elements,preferably Group 4 metals, Ni(II) or Pd(II), most preferably zirconium;

T² is a nitrogen, oxygen or phosphorus containing group;

X² is halo, hydrocarbyl, or hydrocarbyloxy;

t is one or two;

x″ is a number selected to provide charge balance;

and T² and N are linked by a bridging ligand.

Such catalysts have been previously disclosed in J. Am. Chem. Soc., 118,267-268 (1996), J. Am. Chem. Soc., 117, 6414-6415 (1995), andOrganometallics, 16, 1514-1516, (1997), among other disclosures.

Preferred examples of the foregoing metal complexes are aromatic diimineor aromatic dioxyimine complexes of Group 4 metals, especiallyzirconium, corresponding to the formula:

wherein;

M², X² and T² are as previously defined;

R^(d) independently each occurrence is hydrogen, halogen, or R^(e); and

R^(e) independently each occurrence is C₁₋₂₀ hydrocarbyl or aheteroatom-, especially a F, N, S or P-substituted derivative thereof,more preferably C₁₋₁₀ hydrocarbyl or a F or N substituted derivativethereof, most preferably alkyl, dialkylaminoalkyl, pyrrolyl,piperidenyl, perfluorophenyl, cycloalkyl, (poly)alkylaryl, or aralkyl.

Most preferred examples of the foregoing metal complexes for use as acatalyst herein are aromatic dioxyimine complexes of zirconium,corresponding to the formula:

wherein;

X² is as previously defined, preferably C₁₋₁₀ hydrocarbyl, mostpreferably methyl or benzyl; and

R^(e′) is methyl, isopropyl, t-butyl, cyclopentyl, cyclohexyl,2-methylcyclohexyl, 2,4-dimethylcyclohexyl, 2-pyrrolyl,N-methyl-2-pyrrolyl, 2-piperidenyl, N-methyl-2-piperidenyl, benzyl,o-tolyl, 2,6-dimethylphenyl, perfluorophenyl, 2,6-di(isopropyl)phenyl,or 2,4,6-trimethylphenyl.

The foregoing complexes also include certain phosphinimine complexes aredisclosed in EP-A-890581. These complexes correspond to the formula:[(R^(f))₃—P═N]_(f)M(K²)(R^(f))_(3-f″) wherein:

R^(f) is a monovalent ligand or two R^(f) groups together are a divalentligand, preferably Rf is hydrogen or C₁₋₄ alkyl;

M is a Group 4 metal,

K² is a group containing delocalized π-electrons through which K² isbound to M, said K² group containing up to 50 atoms not countinghydrogen atoms, and

f is 1 or 2.

Additional suitable metal complexes include metal complexescorresponding to the formula:

where M′ is a metal of Groups 4-13, preferably Groups 8-10, mostpreferably Ni or Pd;

R^(A), R^(B) and Rc are univalent or neutral substituents, which alsomay be joined together to form one or more divalent substituents, and

c is a number chosen to balance the charge of the metal complex.

Preferred examples of the foregoing metal complexes for use as catalystsare compounds corresponding to the formula:

wherein M′ is Pd or Ni.

Preferred examples of the foregoing metal complexes are compoundscorresponding to the formulas:

Metal complexes capable of increased 2,1-monomer insertion includecompounds of the formulas:

Through use of the foregoing metal complexes, regio-irregular branchingmay be induced in the multi-block copolymers by the use of catalyststhat result in “chain-walking” in the resulting polymer. For example,certain homogeneous bridged bis indenyl- or partially hydrogenated bisindenyl-zirconium catalysts, disclosed by Kaminski, et al., J. Mol.Catal. A: Chemical, 102 (1995) 59-65; Zambelli, et al., Macromolecules,1988, 21, 617-622; or Dias, et al., J. Mol. Catal. A: Chemical, 185(2002) 57-64 may be used to prepare branched copolymers, includinghyper-branched polymers, from single monomers. Higher transition metalcatalysts, especially nickel and palladium catalysts are also known tolead to hyper-branched polymers (the branches of which are alsobranched) as disclosed in Brookhart, et al., J. Am. Chem. Soc., 1995,117, 64145-6415.

Accordingly, in one embodiment of the invention a multi-block copolymercontaining blocks or segments differing in the presence of suchbranching in combination with other segments or blocks substantiallylacking such branching (especially high isotactic polymer blocks) can beproduced. The presence of regio-irregular 2,1- or 3,1-monomer insertionin the multi-block copolymers of the invention can be detected by NMRtechniques. The quantity of the foregoing types of polymer moietiespresent in the polymers of the invention (as a portion of the blocks orsegments containing the same), is normally in the range from 1 to 200,preferably 10-166 incidences per 1,000 carbons for 2,1-monomerinsertions and 1-250, preferably 100-200 incidences per 1,000 carbonsfor 3,1-monomer insertions. In addition, incidental regio-errors in thetactic polymer segment may also be present. In one embodiment, sucherrors are identifiable by ¹³C NMR peaks at 14.6 and 15.7 ppm, the peaksbeing of approximately equal intensity and representing up to 5 molepercent of such polymer segment.

Especially desired metal complexes for preparation of tactic polymersegments are the well known racemic biscyclopentadienyl complexes ofGroup 4 metals, such as dimethylsilane or 1,2-ethylene bridgedbiscyclopentadienyl zirconium complexes, and inertly substitutedderivatives thereof. Examples include racemic dimethylsilane or1,2-ethylene bisindenyl complexes of Group 4 metals, especiallyzirconium, such as ethylenebis(4,5,6,7-tetrahydro-1-indenyl)dimethylzirconium or racemic ethylene bis(indenyl)dimethyl zirconium, andinertly substituted derivatives thereof.

Generally, the metal complex catalyst (also interchangeably referred toherein as procatalysts) may be activated to form the active catalystcomposition by combination with a cocatalyst, preferably a cationforming cocatalyst comprising a relatively non-nucelophillic anion, astrong Lewis acid, or a combination thereof. In a preferred embodiment,the shuttling agent is employed both for purposes of chain shuttling andas the cocatalyst component of the catalyst composition.

The metal complexes desirably are rendered catalytically active bycombination with a cation forming cocatalyst, such as those previouslyknown in the art for use with Group 4 metal olefin polymerizationcomplexes. Suitable cation forming cocatalysts for use herein includeneutral Lewis acids, such as C₁₋₃₀ hydrocarbyl substituted Group 13compounds, especially tri(hydrocarbyl)aluminum- or tri(hydrocarbyl)boroncompounds and halogenated (including perhalogenated) derivativesthereof, having from 1 to 10 carbons in each hydrocarbyl or halogenatedhydrocarbyl group, more especially perfluorinated tri(aryl)boroncompounds, and most especially tris(pentafluoro-phenyl)borane;nonpolymeric, compatible, noncoordinating, ion forming compounds(including the use of such compounds under oxidizing conditions),especially the use of ammonium-, phosphonium-, oxonium-, carbonium-,silylium- or sulfonium-salts of compatible, noncoordinating anions, orferrocenium-, lead- or silver salts of compatible, noncoordinatinganions; and combinations of the foregoing cation forming cocatalysts andtechniques. The foregoing activating cocatalysts and activatingtechniques have been previously taught with respect to different metalcomplexes for olefin polymerizations in the following references:EP-A-277,003, U.S. Pat. No. 5,153,157, 5,064,802, 5,321,106, 5,721,185,5,350,723, 5,425,872, 5,625,087, 5,883,204, 5,919,983, 5,783,512, WO99/15534, and WO99/42467.

Combinations of neutral Lewis acids, especially the combination of atrialkyl aluminum compound having from 1 to 4 carbons in each alkylgroup and a halogenated tri(hydrocarbyl)boron compound having from 1 to20 carbons in each hydrocarbyl group, especiallytris(pentafluorophenyl)borane, further combinations of such neutralLewis acid mixtures with a polymeric or oligomeric alumoxane, andcombinations of a single neutral Lewis acid, especiallytris(pentafluorophenyl)borane with a polymeric or oligomeric alumoxanemay be used as activating cocatalysts. Preferred molar ratios of metalcomplex:tris(pentafluorophenyl-borane:alumoxane are from 1:1:1 to1:5:20, more preferably from 1:1:1.5 to 1:5:10.

Suitable ion forming compounds useful as cocatalysts in one embodimentof the present invention comprise a cation which is a Bronsted acidcapable of donating a proton, and a, noncoordinating anion, A⁻.

Preferred anions are those containing a single coordination complexcomprising a charge-bearing metal or metalloid core which anion iscapable of balancing the charge of the active catalyst species (themetal cation) which may be formed when the procatalyst and thecocatalyst are combined. Also, said anion should be sufficiently labileto be displaced by olefinic, diolefinic and acetylenically unsaturatedcompounds or other neutral Lewis bases such as ethers or nitriles.Suitable metals include, but are not limited to, aluminum, gold andplatinum. Suitable metalloids include, but are not limited to, boron,phosphorus, and silicon. Compounds containing anions which comprisecoordination complexes containing a single metal or metalloid atom are,of course, well known and many, particularly such compounds containing asingle boron atom in the anion portion, are available commercially.

Preferably such cocatalysts may be represented by the following generalformula:(L*-H)_(g) ⁺(A)^(g−)wherein:

L* is a neutral Lewis base;

(L*-H)⁺ is a conjugate Bronsted acid of L*;

A^(g−) is a noncoordinating, compatible anion having a charge of g-, and

g is an integer from 1 to 3.

More preferably A^(g−) corresponds to the formula: [M′Q₄]⁻;

wherein:

M′ is boron or aluminum in the +3 formal oxidation state; and

Q independently each occurrence is selected from hydride, dialkylamido,halide, hydrocarbyl, hydrocarbyloxide, halosubstituted-hydrocarbyl,halosubstituted hydrocarbyloxy, and halo-substituted silylhydrocarbylradicals (including perhalogenated hydrocarbyl-perhalogenatedhydrocarbyloxy- and perhalogenated silylhydrocarbyl radicals), said Qhaving up to 20 carbons with the proviso that in not more than oneoccurrence is Q halide. Examples of suitable hydrocarbyloxide Q groupsare disclosed in U.S. Pat. No. 5,296,433.

In a more preferred embodiment, d is one, that is, the counter ion has asingle negative charge and is A⁻. Activating cocatalysts comprisingboron which are particularly useful in the preparation of catalysts ofthis invention may be represented by the following general formula:(L*-H)⁺(BQ₄)⁻;wherein:

L* is as previously defined;

B is boron in a formal oxidation state of 3; and

Q is a hydrocarbyl-, hydrocarbyloxy-, fluorinated hydrocarbyl-,fluorinated hydrocarbyloxy-, or fluorinated silylhydrocarbyl-group of upto 20 nonhydrogen atoms, with the proviso that in not more than oneoccasion is Q hydrocarbyl.

Preferred Lewis base salts are ammonium salts, more preferablytrialkylammonium salts containing one or more C₁₂₋₄₀ alkyl groups. Mostpreferably, Q is each occurrence a fluorinated aryl group, especially, apentafluorophenyl group.

Illustrative, but not limiting, examples of boron compounds which may beused as an activating cocatalyst in the preparation of the improvedcatalysts of this invention are tri-substituted ammonium salts such as:

-   trimethylammonium tetrakis(pentafluorophenyl) borate,-   triethylammonium tetrakis(pentafluorophenyl) borate,-   tripropylammonium tetrakis(pentafluorophenyl) borate,-   tri(n-butyl)ammonium tetrakis(pentafluorophenyl) borate,-   tri(sec-butyl)ammonium tetrakis(pentafluorophenyl) borate,-   N,N-dimethylanilinium tetrakis(pentafluorophenyl) borate,-   N,N-dimethylanilinium n-butyltris(pentafluorophenyl) borate,-   N,N-dimethylanilinium benzyltris(pentafluorophenyl) borate,-   N,N-dimethylanilinium    tetrakis(4-(t-butyldimethylsilyl)-2,3,5,6-tetrafluorophenyl) borate,-   N,N-dimethylanilinium    tetrakis(4-(triisopropylsilyl)-2,3,5,6-tetrafluorophenyl) borate,-   N,N-dimethylanilinium pentafluorophenoxytris(pentafluorophenyl)    borate,-   N,N-diethylanilinium tetrakis(pentafluorophenyl) borate,-   N,N-dimethyl-2,4,6-trimethylanilinium tetrakis(pentafluorophenyl)    borate,-   dimethyloctadecylammonium tetrakis(pentafluorophenyl) borate,-   methyldioctadecylammonium tetrakis(pentafluorophenyl) borate,    dialkyl ammonium salts such as:-   di-(i-propyl)ammonium tetrakis(pentafluorophenyl) borate,-   methyloctadecylammonium tetrakis(pentafluorophenyl) borate,-   methyloctadodecylammonium tetrakis(pentafluorophenyl) borate, and-   dioctadecylammonium tetrakis(pentafluorophenyl) borate;    tri-substituted phosphonium salts such as:-   triphenylphosphonium tetrakis(pentafluorophenyl) borate,-   methyldioctadecylphosphonium tetrakis(pentafluorophenyl) borate, and-   tri(2,6-dimethylphenyl)phosphonium tetrakis(pentafluorophenyl)    borate;    di-substituted oxonium salts such as:-   diphenyloxonium tetrakis(pentafluorophenyl) borate,-   di(o-tolyl)oxonium tetrakis(pentafluorophenyl) borate, and-   di(octadecyl)oxonium tetrakis(pentafluorophenyl) borate;    di-substituted sulfonium salts such as:-   di(o-tolyl)sulfonium tetrakis(pentafluorophenyl) borate, and-   methylcotadecylsulfonium tetrakis(pentafluorophenyl) borate.

Preferred (L*-H)⁺ cations are methyldioctadecylammonium cations,dimethyloctadecylammonium cations, and ammonium cations derived frommixtures of trialkyl amines containing one or 2 C₁₄₋₁₈ alkyl groups.

Another suitable ion forming, activating cocatalyst comprises a salt ofa cationic oxidizing agent and a noncoordinating, compatible anionrepresented by the formula:(Ox^(h+))_(g)(A^(g−))_(h),wherein:

Ox^(h+) is a cationic oxidizing agent having a charge of h+;

h is an integer from 1 to 3; and

A^(g−) and g are as previously defined.

Examples of cationic oxidizing agents include: ferrocenium,hydrocarbyl-substituted ferrocenium, A_(g) ⁺, or Pb⁺². Preferredembodiments of A^(g−) are those anions previously defined with respectto the Bronsted acid containing activating cocatalysts, especiallytetrakis(pentafluorophenyl)borate.

Another suitable ion forming, activating cocatalyst comprises a compoundwhich is a salt of a carbenium ion and a noncoordinating, compatibleanion represented by the formula:[C]⁺A⁻wherein:

[C]⁺ is a C₁₋₂₀ carbenium ion; and

A⁻ is a noncoordinating, compatible anion having a charge of −1. Apreferred carbenium ion is the trityl cation, that istriphenylmethylium.

A further suitable ion forming, activating cocatalyst comprises acompound which is a salt of a silylium ion and a noncoordinating,compatible anion represented by the formula:(Q¹ ₃Si)⁺A⁻wherein:

Q¹ is C₁₋₁₀ hydrocarbyl, and A⁻ is as previously defined.

Preferred silylium salt activating cocatalysts are trimethylsilyliumtetrakispentafluorophenylborate, triethylsilyliumtetrakispentafluorophenylborate and ether substituted adducts thereof.Silylium salts have been previously generically disclosed in J. ChemSoc. Chem. Comm., 1993, 383-384, as well as Lambert, J. B., et al.,Organometallics, 1994, 13, 2430-2443. The use of the above silyliumsalts as activating cocatalysts for addition polymerization catalysts isdisclosed in U.S. Pat. No. 5,625,087.

Certain complexes of alcohols, mercaptans, silanols, and oximes withtris(pentafluorophenyl)borane are also effective catalyst activators andmay be used according to the present invention. Such cocatalysts aredisclosed in U.S. Pat. No. 5,296,433.

Suitable activating cocatalysts for use herein also include polymeric oroligomeric alumoxanes, especially methylalumoxane (MAO), triisobutylaluminum modified methylalumoxane (MMAO), or isobutylalumoxane; Lewisacid modified alumoxanes, especially perhalogenatedtri(hydrocarbyl)aluminum- or perhalogenated tri(hydrocarbyl)boronmodified alumoxanes, having from 1 to 10 carbons in each hydrocarbyl orhalogenated hydrocarbyl group, and most especiallytris(pentafluorophenyl)borane modified alumoxanes. Such cocatalysts arepreviously disclosed in U.S. Pat. Nos. 6,214,760, 6,160,146, 6,140,521,and 6,696,379.

A class of cocatalysts comprising non-coordinating anions genericallyreferred to as expanded anions, further disclosed in U.S. Pat. No.6,395,671, may be suitably employed to activate the metal complexes ofthe present invention for olefin polymerization. Generally, thesecocatalysts (illustrated by those having imidazolide, substitutedimidazolide, imidazolinide, substituted imidazolinide, benzimidazolide,or substituted benzimidazolide anions) may be depicted as follows:

wherein:

A^(*+) is a cation, especially a proton containing cation, andpreferably is a trihydrocarbyl ammonium cation containing one or twoC₁₀₋₄₀ alkyl groups, especially a methyldi (C₁₄₋₂₀ alkyl)ammoniumcation,

Q³, independently each occurrence, is hydrogen or a halo, hydrocarbyl,halocarbyl, halohydrocarbyl, silylhydrocarbyl, or silyl, (includingmono-, di- and tri(hydrocarbyl)silyl) group of up to 30 atoms notcounting hydrogen, preferably C₁₋₂₀ alkyl, and

Q² is tris(pentafluorophenyl)borane or tris(pentafluorophenyl)alumane).

Examples of these catalyst activators include trihydrocarbylammonium-salts, especially, methyldi(C₁₄₋₂₀alkyl)ammonium- salts of:

-   bis(tris(pentafluorophenyl)borane)imidazolide,-   bis(tris(pentafluorophenyl)borane)-2-undecylimidazolide,-   bis(tris(pentafluorophenyl)borane)-2-heptadecylimidazolide,-   bis(tris(pentafluorophenyl)borane)-4,5-bis(undecyl)imidazolide,-   bis(tris(pentafluorophenyl)borane)-4,5-bis(heptadecyl)imidazolide,-   bis(tris(pentafluorophenyl)borane)imidazolinide,-   bis(tris(pentafluorophenyl)borane)-2-undecylimidazolinide,-   bis(tris(pentafluorophenyl)borane)-2-heptadecylimidazolinide,-   bis(tris(pentafluorophenyl)borane)-4,5-bis(undecyl)imidazolinide,-   bis(tris(pentafluorophenyl)borane)-4,5-bis(heptadecyl)imidazolinide,-   bis(tris(pentafluorophenyl)borane)-5,6-dimethylbenzimidazolide,-   bis(tris(pentafluorophenyl)borane)-5,6-bis(undecyl)benzimidazolide,-   bis(tris(pentafluorophenyl)alumane)imidazolide,-   bis(tris(pentafluorophenyl)alumane)-2-undecylimidazolide,-   bis(tris(pentafluorophenyl)alumane)-2-heptadecylimidazolide,-   bis(tris(pentafluorophenyl)alumane)-4,5-bis(undecyl)imidazolide,-   bis(tris(pentafluorophenyl)alumane)-4,5-bis(heptadecyl)imidazolide,-   bis(tris(pentafluorophenyl)alumane)imidazolinide,-   bis(tris(pentafluorophenyl)alumane)-2-undecylimidazolinide,-   bis(tris(pentafluorophenyl)alumane)-2-heptadecylimidazolinide,-   bis(tris(pentafluorophenyl)alumane)-4,5-bis(undecyl)imidazolinide,-   bis(tris(pentafluorophenyl)alumane)-4,5-bis(heptadecyl)imidazolinide,-   bis(tris(pentafluorophenyl)alumane)-5,6-dimethylbenzimidazolide, and-   bis(tris(pentafluorophenyl)alumane)-5,6-bis(undecyl)benzimidazolide.

Other activators include those described in PCT publication WO 98/07515such as tris (2,2′,2″-nonafluorobiphenyl)fluoroaluminate. Combinationsof activators are also contemplated by the invention, for example,alumoxanes and ionizing activators in combinations, see for example,EP-A-0 573120, PCT publications WO 94/07928 and WO 95/14044 and U.S.Pat. Nos. 5,153,157 and 5,453,410. WO 98/09996 describes activatingcatalyst compounds with perchlorates, periodates and iodates, includingtheir hydrates. WO 99/18135 describes the use of organoboroaluminumactivators. WO 03/10171 discloses catalyst activators that are adductsof Bronsted acids with Lewis acids. Other activators or methods foractivating a catalyst compound are described in for example, U.S. Pat.Nos. 5,849,852, 5,859,653, 5,869,723, EP-A-615981, and PCT publicationWO 98/32775. All of the foregoing catalyst activators as well as anyother know activator for transition metal complex catalysts may beemployed alone or in combination according to the present invention.

The molar ratio of catalyst/cocatalyst employed preferably ranges from1:10,000 to 100:1, more preferably from 1:5000 to 10:1, most preferablyfrom 1:1000 to 1:1. Alumoxane, when used by itself as an activatingcocatalyst, is typically employed in large quantity, generally at least100 times the quantity of metal complex on a molar basis.Tris(pentafluorophenyl)borane, where used as an activating cocatalyst isemployed in a molar ratio to the metal complex of from 0.5:1 to 10:1,more preferably from 1:1 to 6:1 most preferably from 1:1 to 5:1. Theremaining activating cocatalysts are generally employed in approximatelyequimolar quantity with the metal complex.

During the polymerization, the monomer or monomers are contacted withthe activated catalyst composition according to any suitablepolymerization conditions. The process is characterized by use ofelevated temperatures and pressures. Hydrogen may be employed as a chaintransfer agent for molecular weight control according to knowntechniques if desired. As in other similar polymerizations, it is highlydesirable that the monomer(s) and solvents employed be of sufficientlyhigh purity that significant catalyst deactivation does not occur. Anysuitable technique for monomer purification such as devolatilization atreduced pressure, contacting with molecular sieves or high surface areaalumina, or a combination of the foregoing processes may be employed.The skilled artisan will appreciate that the ratio of chain shuttlingagent to one or more catalysts and or monomers in the process of thepresent invention may be varied in order to produce polymers differingin one or more chemical or physical properties.

The polymerization is desirably carried out as a continuouspolymerization, preferably a continuous, solution polymerization, inwhich catalyst components, shuttling agent(s), monomer(s), andoptionally solvent, adjuvants, scavengers, and polymerization aids arecontinuously supplied to the reaction zone and polymer productcontinuously removed there from. Within the scope of the terms“continuous” and “continuously” as used in this context are thoseprocesses in which there are intermittent additions of reactants andremoval of products at small regular or irregular intervals, so that,over time, the overall process is substantially continuous.

For a solution polymerization process it is desirable to employhomogeneous dispersions of the catalyst components in a liquid diluentin which the polymer is soluble under the polymerization conditionsemployed. One such process utilizing an extremely fine silica or similardispersing agent to produce such a homogeneous catalyst dispersion whereeither the metal complex or the cocatalyst is only poorly soluble isdisclosed in U.S. Pat. No. 5,783,512. A solution process to prepare thenovel polymers of the present invention, especially a continuoussolution process is preferably carried out at a temperature between 80°C. and 250° C., more preferably between 100° C. and 210° C., and mostpreferably between 110° C. and 210° C. A high pressure process isusually carried out at temperatures from 100° C. to 400° C. and atpressures above 500 bar (50 MPa). A slurry process typically uses aninert hydrocarbon diluent and temperatures of from 0° C. up to atemperature just below the temperature at which the resulting polymerbecomes substantially soluble in the inert polymerization medium.Preferred temperatures in a slurry polymerization are from 30° C.,preferably from 60° C. up to 115° C., preferably up to 100° C. Pressurestypically range from atmospheric (100 kPa) to 500 psi (3.4 MPa).

In all of the foregoing processes, continuous or substantiallycontinuous polymerization conditions are preferably employed. The use ofsuch polymerization conditions, especially continuous, solutionpolymerization processes employing two or more active polymerizationcatalyst species, allows the use of elevated reactor temperatures whichresults in the economical production of multi-block copolymers in highyields and efficiencies. Both well-mixed and plug-flow type reactionconditions may be employed. The latter conditions are preferred wheretapering of the block composition is desired.

The catalyst compositions may be prepared as homogeneous compositions byaddition of the metal complexes to a solvent in which the polymerizationwill be conducted or in a diluent compatible with the ultimate reactionmixture. The desired cocatalyst and the shuttling agent may be combinedwith the catalyst composition either prior to, simultaneously with, orafter combination with the monomers to be polymerized and any additionalreaction diluent.

At all times, the individual ingredients as well as any active catalystcomposition must be protected from oxygen and moisture. Therefore, thecatalyst components, shuttling agent and activated catalysts must beprepared and stored in an oxygen and moisture free atmosphere,preferably a dry, inert gas such as nitrogen.

Without limiting in any way the scope of the invention, one means forcarrying out such a polymerization process is as follows. In astirred-tank reactor, the monomers to be polymerized are introducedcontinuously together with any solvent or diluent. The reactor containsa liquid phase composed substantially of monomers together with anysolvent or diluent and dissolved polymer. Preferred solvents includeC₄₋₁₀ hydrocarbons or mixtures thereof, especially alkanes such ashexane or mixtures of alkanes, as well as one or more of the monomersemployed in the polymerization.

The mixture of two or more catalysts along with cocatalyst and chainshuttling agent are continuously or intermittently introduced in thereactor liquid phase or any recycled portion thereof. The reactortemperature and pressure may be controlled by adjusting thesolvent/monomer ratio, the catalyst addition rate, as well as by coolingor heating coils, jackets or both. The polymerization rate is controlledby the rate of catalyst addition. The comonomer content (if any) of thepolymer product is determined by the ratio of major monomer to comonomerin the reactor, which is controlled by manipulating the respective feedrates of these components to the reactor. The polymer product molecularweight is controlled, optionally, by controlling other polymerizationvariables such as the temperature, monomer concentration, or by thepreviously mentioned chain transfer agent, as is well known in the art.Upon exiting the reactor, the effluent is contacted with a catalyst killagent such as water, steam or an alcohol. The polymer solution isoptionally heated, and the polymer product is recovered by flashing offgaseous monomers as well as residual solvent or diluent at reducedpressure, and, if necessary, conducting further devolatilization inequipment such as a devolatilizing extruder. In a continuous process themean residence time of the catalyst and polymer in the reactor generallyis from 5 minutes to 8 hours, and preferably from 10 minutes to 6 hours.

Alternatively, the foregoing polymerization may be carried out in acontinuous loop reactor with or without a monomer, catalyst or shuttlingagent gradient established between differing regions thereof, optionallyaccompanied by separated addition of catalysts and/or chain transferagent, and operating under adiabatic or non-adiabatic solutionpolymerization conditions or combinations of the foregoing reactorconditions. Examples of suitable loop reactors and a variety of suitableoperating conditions for use therewith are found in U.S. Pat. Nos.5,977,251, 6,319,989 and 6,683,149.

Although not as desired, the catalyst composition may also be preparedand employed as a heterogeneous catalyst by adsorbing the requisitecomponents on an inert inorganic or organic particulated solid, aspreviously disclosed. In an preferred embodiment, a heterogeneouscatalyst is prepared by co-precipitating the metal complex and thereaction product of an inert inorganic compound and an active hydrogencontaining activator, especially the reaction product of a tri (C₁₋₄alkyl) aluminum compound and an ammonium salt of ahydroxyaryltris(pentafluorophenyl)borate, such as an ammonium salt of(4-hydroxy-3,5-ditertiarybutylphenyl)tris(pentafluorophenyl)borate. Whenprepared in heterogeneous or supported form, the catalyst compositionmay be employed in a slurry or a gas phase polymerization. As apractical limitation, slurry polymerization takes place in liquiddiluents in which the polymer product is substantially insoluble.Preferably, the diluent for slurry polymerization comprises one or morehydrocarbons or halogenated hydrocarbons with from 3 to 10 carbon atoms.As with a solution polymerization, the monomer or a mixture of differentmonomers may be used in whole or part as the diluent. Most preferably atleast a major part of the diluent comprises the monomers to bepolymerized.

As previously mentioned, functionalized derivatives of multi-blockcopolymers are also included within the present invention. Examplesinclude metallated polymers wherein the metal is the remnant of thecatalyst or chain shuttling agent employed, as well as furtherderivatives thereof, for example, the reaction product of a metallatedpolymer with an oxygen source and then with water to form a hydroxylterminated polymer. In another embodiment, sufficient air or otherquench agent is added to cleave some or all of the shuttlingagent-polymer bonds thereby converting at least a portion of the polymerto a hydroxyl terminated polymer. Additional examples include olefinterminated polymers formed by β-hydride elimination and ethylenicunsaturation in the resulting polymer.

In one embodiment of the invention the multi-block copolymer may befunctionalized by maleation (reaction with maleic anhydride or itsequivalent), metallation (such as with an alkyl lithium reagent,optionally in the presence of a Lewis base, especially an amine, such astetramethylethylenediamine), or by incorporation of a diene or maskedolefin in a copolymerization process. After polymerization involving amasked olefin, the masking group, for example a trihydrocarbylsilane,may be removed thereby exposing a more readily functionalized remnant.Techniques for functionalization of polymers are well known, anddisclosed for example in U.S. Pat. No. 5,543,458, and elsewhere.

Because a substantial fraction of the polymeric product exiting thereactor can be terminated with the chain shuttling agent, furtherfunctionalization is relatively easy. The metallated polymer species canbe utilized in well known chemical reactions such as those suitable forother alkyl-aluminum, alkyl-gallium, alkyl-zinc, or alkyl-Group 1compounds to form amine-, hydroxy-, epoxy-, ketone-, ester-, nitrile-and other functionalized terminated polymer products. Examples ofsuitable reaction techniques that are adaptable for use here in aredescribed in Negishi, “Organometallics in Organic Synthesis”, Vol. 1 and2, (1980), and other standard texts in organometallic and organicsynthesis.

Utilizing the present process, multi-block copolymers are readilyprepared having a variety of desirable physical properties. Tacticity,if any, in the resulting interpolymers may be measured using anysuitable technique, with techniques based on nuclear magnetic resonance(NMR) spectroscopy preferred. It is highly desirable that some of thepolymer blocks comprise an isotactic polymer, preferably a highlyisotactic polypropylene or poly-4-methyl-1-pentene, and any remainingpolymer blocks predominantly comprise polymer containing regio-irregular3,1-monomer insertions, essentially generating amorphous copolymersegments therein. Preferably the tactic segments or blocks are highlyisotactic polypropylene or poly-4-methyl-1-pentene, especiallyhomopolymers containing at least 99 mole percent propylene, 1-butene or4-methyl-1-pentene therein. Further preferably, the amorphous polymersegments have Tg less than 25° C., preferably less than 0° C., morepreferably less than −10° C., most preferably less than −25° C., andmost highly preferably less than −30° C.

Additionally, the interpolymers of the invention preferably comprisefrom 5 to 95 percent tactic, crystalline or other relatively hardsegments, and 95 to 5 percent amorphous or relatively soft polymersegments, more preferably from 10 to 90 percent crystalline orrelatively hard segments and 90 to 10 percent amorphous or relativelyamorphous segments (soft segments).

Regio-irregular branching in the polymers of the invention may alsoarise as a result of chain walking or other branch forming process aspreviously disclosed. In the instance where chain walking in thepolymerization of a C₄₋₂₀ α-olefin occurs, the catalyst chain may “walk”to the terminal methyl unit of the monomer before inserting anothermonomer. Such insertions may include 1,ω- or 2,ω-insertions, and lead toeither chain straightening or to differences in chain branching and/orlowered Tg in the segments containing the same. Specifically,1,ω-insertions generally lead to a reduction in branching compared to anormal polymer. In addition, 2-ωinsertions result in the formation ofmethyl branches. These insertions are included within the term“regio-irregular monomer insertion” or “regio-irregular branching” asused herein.

The polymers of the invention can have a melt index, I₂, from 0.01 to2000 g/10 minutes, preferably from 0.01 to 1000 g/10 minutes, morepreferably from 0.01 to 500 g/10 minutes, and especially from 0.01 to100 g/10 minutes. Desirably, the invented polymers can have molecularweights, M_(w), from 1,000 g/mole to 5,000,000 g/mole, preferably from1000 g/mole to 1,000,000, more preferably from 10,000 g/mole to 500,000g/mole, and especially from 10,000 g/mole to 300,000 g/mole. The densityof the polymers desirably is from 0.80 to 0.99 g/cm³ and preferably from0.85 g/cm³ to 0.97 g/cm³.

Additives and adjuvants may be included in any formulation comprisingpolymers of the present invention. Suitable additives include fillers,such as organic or inorganic particles, including clays, talc, titaniumdioxide, zeolites, powdered metals, organic or inorganic fibers,including carbon fibers, silicon nitride fibers, steel wire or mesh, andnylon or polyester cording, nano-sized particles, clays, and so forth;tackifiers, oil extenders, including paraffinic or napthelenic oils;stabilizers, anti-oxidants, colorants, extrusion aids, slip additives,release additives, and other natural and synthetic polymers, includingother polymers according to the invention.

Analytical Techniques

DSC Standard Method

Differential Scanning Calorimetry results are determined using a modelQ1000 DSC, available from TAI, Owings Mills, Md., equipped with an RCScooling accessory and an autosampler, or equivalent instrument. Anitrogen purge gas flow of 50 ml/min. is used. 3-10 mg Of material isaccurately weighed, placed in a light aluminum pan weighingapproximately 50 mg, and then crimped shut. The thermal behavior of thesample is investigated with the following temperature profile. Thesample is rapidly heated to 180° C. and held isothermally for 3 minutesin order to remove any previous thermal history. The sample is thencooled to −40° C. at a cooling rate of 10° C./min. and held at −40° C.for 3 minutes. The sample is then heated to 150° C. at a heating rate of10° C./min. The cooling and second heating curves are recorded.

The DSC melting peak is measured as the maximum in heat flow rate (W/g)with respect to the linear baseline drawn between −30° C. and the end ofmelting. The heat of fusion is measured as the area under the meltingcurve between −30° C. and the end of melting using a linear baseline. Ifthe melting point of the sample is >150° C., then the temperature of theisothermal first heat and second heat is increased accordingly.

GPC Method for Determining Polymer Mn, Mw

Gel permeation chromatograms are made using a Model PL-210 or ModelPL-220 gel permeation instrument, available from Polymer Laboratories,or equivalent equipment. The column and carousel compartments areoperated at 140° C. Three Polymer Laboratories 10-micron Mixed-B columnsare used. The solvent is 1,2,4-trichlorobenzene. The samples areprepared at a concentration of 0.1 grams of polymer in 50 milliliters ofsolvent containing 200 ppm of butylated hydroxytoluene (BHT). Samplesare prepared by agitating lightly for 2 hours at 160° C. The injectionvolume used is 100 microliters and the flow rate is 1.0 ml/minute.

Calibration of the GPC column set is performed with 21 narrow molecularweight distribution polystyrene standards with molecular weights rangingfrom 580 to 8,400,000, arranged in 6 “cocktail” mixtures with at least adecade of separation between individual molecular weights. The standardsare purchased from Polymer Laboratories (Shropshire, UK). Thepolystyrene standards are prepared at 0.025 grams in 50 milliliters ofsolvent for molecular weights equal to or greater than 1,000,000, and0.05 grams in 50 milliliters of solvent for molecular weights less than1,000,000. The polystyrene standards are dissolved at 80° C. with gentleagitation for 30 minutes. The narrow standards mixtures are run firstand in order of decreasing highest molecular weight component tominimize degradation. The polystyrene standard peak molecular weightsare converted to polyethylene molecular weights using the followingequation (as described in Williams and Ward, J. Polym. Sci., Polym.Let., 6, 621 (1968)): M_(polyethylene)=0.431(M_(polystyrene))

Polyetheylene equivalent molecular weight calculations are performedusing Viscotek TriSEC™ software Version 3.0, available from ViscotekCorporation, Houston, Tex.

Specific Embodiments

The following specific embodiments of the invention and combinationsthereof are especially desirable and hereby delineated in order toprovide detailed disclosure for the appended claims.

1. A process for forming a high molecular weight, multi-block copolymercomprising two or more chemically distinguishable segments or blocks,the process comprising polymerizing one or more olefin monomers in thepresence of a chain shuttling agent and a catalyst compositioncomprising:

two or more olefin polymerization catalysts capable of preparingpolymers having differing chemical or physical properties underequivalent polymerization conditions,

or

a catalyst composition comprising at least one olefin polymerizationcatalyst containing multiple active catalyst sites capable of preparingpolymers having differing chemical or physical properties;

characterized in that the polymerization is conducted in the presence ofa solvent comprising a polar, aprotic, organic liquid compound, having adielectric constant greater than 2.4, preferably greater than or equalto 2.8, most preferably greater than or equal to 3.0.

2. A process according to embodiment 1 wherein the polar, aproticcompound is selected from the group consisting of: o-xylene,ethylbenzene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene,1,3,5-trimethylbenzene, isopropylbenzene, 1-methyl-2-ethylbenzene,1,2-diethylbenzene, chlorobenzene, o-dichlorobenzene, chlorotoluene,1-chloroethane, dichloromethane, 1,2-dichloroethane, 1-chloroethene,1-chloropropane, 1,1-dichloroethane, 1-chlorobutane, 1-chloropentane,1-chlorohexane, 1,1,1-trifluoroethane, difluoromethane,trifluoromethane, 1,1-difluoroethane, 1,1,1-trifluororethane,1,1,1,2-tetrafluoroethane, 1,1,1-trifluoropropane,1,1,1-trifluorobutane, 1,1,1-trifluoropentane, 1,1,1-trifluorohexane,1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluorobutane,fluorocyclobutane, difluorocyclobutane, trifluorocyclobutane,pentafluorocyclobutane, fluorocyclohexane, 1,2-difluorocyclohexane,1,3-difluorocyclohexane, fluorobenzene, o-difluorobenzene,m-difluorobenzene, p-difluorobenzene, fluorotoluene, difluorotoluene,1-chloro-1-fluoroethane, 1,2-dichlorofluororethane,dichlorofluoromethane, difluorochloromethane, 2-trifluoromethylpropane,tetrahydrofuran, methyl t-butyl ether, 2-butanone, diethylether,1,2-dimethoxyethane, ethylene glycol dibutyl ether; diethylene glycoldimethyl ether, diethylene glycol dibutyl ether, 1,4-dioxane,chloroform, sulfolane, dimethylformamide, and dimethylether

3. A process according to embodiment 2 wherein the solvent comprises amixture of one or more polar, aprotic compounds with one or more aproticcompounds having a dielectric constant less than 2.4.

4. A process according to embodiment 2 wherein the polar, aproticcompound is o-xylene, chlorobenzene, dichlorobenzene, fluorobenzene,difluorobenzene, o-chlorotoluene or o-fluorotoluene.

5. A process according to embodiment 1 which is a continuous, solutionpolymerization.

6. A process according to embodiment 5 conducted at a temperature from70 to 200° C.

7. A process according to embodiment 1 wherein the shuttling agent is anorganoaluminum-compound containing from 1 to 12 carbons in each organogroup.

8. A process according to embodiment 7 wherein the shuttling agent istrimethyl aluminum.

9. A process according to any one of embodiments 1-6 wherein theshuttling agent is diethylzinc

10. The process of claim 1 wherein the polar, aprotic organic liquid isnoncoordinating.

11. A process for forming a high molecular weight, multi-block copolymercomprising two or more chemically distinguishable segments or blocks,the process comprising polymerizing one or more olefin monomers in thepresence of a chain shuttling agent and a catalyst compositioncomprising:

two or more olefin polymerization catalysts capable of preparingpolymers having differing chemical or physical properties underequivalent polymerization conditions,

or

a catalyst composition comprising at least one olefin polymerizationcatalyst containing multiple active catalyst sites capable of preparingpolymers having differing chemical or physical properties;

characterized in that the polymerization is conducted in the presence ofa solvent selected from the group consisting of: o-xylene, ethylbenzene,1,2,3-trimethylbenzene, 1,3,5-trimethylbenzene, isopropylbenzene,1-methyl-2-ethylbenzene, 1,2-diethylbenzene, 1,2,4-trimethylbenzene,chlorobenzene, o-dichlorobenzene, chlorotoluene, 1-chloroethane,1,2-dichloroethane, 1-chloropropane, 1,1-dichloroethane, 1-chlorobutane,1-chloropentane, 1-chlorohexane, 1,1,1-trifluoroethane, difluoromethane,trifluoromethane, 1,1-difluoroethane, 1,1,1-trifluororethane,1,1,1,2-tetrafluoroethane, 1,1,1-trifluoropropane,1,1,1-trifluorobutane, 1,1,1-trifluoropentane, 1,1,1-trifluorohexane,1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluorobutane,fluorocyclobutane, difluorocyclobutane, trifluorocyclobutane,pentafluorocyclobutane, fluorocyclohexane, 1,2-difluorocyclohexane,1,3-difluorocyclohexane, fluorobenzene, o-difluorobenzene,m-difluotobenzene, p-difluorobenzene, fluorotoluene, difluorotoluene,1-chloro-1-fluoroethane, 1,2-dichlorofluororethane,dichlorofluoromethane, difluorochloromethane, 2-trifluoromethylpropane,tetrahydrofuran, methyl t-butyl ether, 2-butanone, diethylether,1,2-dimethoxyethane, ethylene glycol dibutyl ether; diethylene glycoldimethyl ether, diethylene glycol dibutyl ether, dichloromethane,chloroform, sulfolane, dimethylformamide, and dimethylether.

The skilled artisan will appreciate that the invention disclosed hereinmay be practiced in the absence of any component, step or ingredientwhich has not been specifically disclosed.

EXAMPLES

The following examples are provided as further illustration of theinvention and are not to be construed as limiting. The term “overnight”,if used, refers to a time of approximately 16-18 hours, the term “roomtemperature”, refers to a temperature of 20-25° C., and the term “mixedalkanes” refers to a commercially obtained mixture of C₆₋₉ aliphatichydrocarbons available under the trade designation Isopar E®, from ExxonMobil Chemicals Inc. In the event the name of a compound herein does notconform to the structural representation thereof, the structuralrepresentation shall control. The synthesis of all metal complexes andthe preparation of all screening experiments were carried out in a drynitrogen atmosphere using dry box techniques. All solvents used wereHPLC grade and were dried before their use.

Racemic Hafnium,[N-[2,6-bis(1-methylethyl)phenyl]-α-(2-methylphenyl)-6-(1-naphthanlenyl-κ-C²)-2-pyridine-methaneaminato(2-)-κN¹,κN²]-dimethyl(Rac-1)

This complex is prepared according to the teachings of WO 2003/040195,WO/2004/024740, WO 2004/099268, and U.S. Pat. No. 6,953,764.

(R)-Hafnium,[N-[2,6-bis(1-methylethyl)phenyl]-α-[2-(1-methyl)phenyl]-6-(1-naphthanlenyl-κ-C²)-2-pyridinemethanaminato(2-)-κN¹,κN²]-dimethyl-(R1)

In a 1000 mL round-bottomed flask equipped with a small magneticstir-bar is placed 21.3 g (43.7 millimoles) ofrac-2-pyridinemethanamine,N-[2,6-bis(1-methylethyl)phenyl]-α[2-(1-methyl)phenyl]-6-(1-naphthanlenyl).10.2 g (43.7 Millimoles) of (+)-(1S)-camphor-10-sulphonic acid are addedalong with 500 mL of THF. The mixture is stirred until all of the solidsare dissolved, giving an amber-colored solution. This solution isreduced in volume by rotary evaporation. The resulting dry foam isdissolved in approximately 500 mL of boiling toluene and placed in alarge, insulated, dewar flask to slowly cool. The resulting crystals arerecovered by filtration after cooling overnight, and recrystallizedtwice using the same procedure. Following the final recrystallization,the crystals are dried under reduced pressure to yield 9.789 g (47percent of theoretical) of (R)-pyridinemethanamine,N-[2,6-bis(1-methylethyl)phenyl]-α-[2-(1-methyl)phenyl]-6-(1-naphthanlenyl)[(S)-camphorsulfonate] salt as colorless crystals. Identity is confirmedby single crystal X-ray analysis.

To a glass jar equipped with a small magnetic stir-bar are added 7.17 g(7.56 millimoles) of the (R)-2-pyridinemethanamine,N-[2,6-bis(1-methylethyl)phenyl]-α[2-(1-methyl)phenyl]-6-(1-naphthanlenyl)[(S)-camphorsulfonate] salt and 25 mL of CH₂Cl₂. A solution of 1.5 g (10millimoles) of KOH in 25 mL of H₂O is added. The mixture is stirred for10 minutes, and then the layers are allowed to separate. The organiclayer is washed with water 3 times, dried with anhydrous MgSO₄, and thesolvent evaporated to give the desired product,(R)-2-pyridinemethanamine,N-[2,6-bis(1-methylethyl)phenyl]-α[2-(1-methyl)phenyl]-6-(1-naphthanlenyl).Yield, 3.403 g (93 percent of theoretical). The product is determined tobe 98.4 percent e.e. by chiral HPLC chromatography.

In a dry box, to a jar containing a polytetrafluoroethylene coatedmagnetic stir-bar is added 3.0 g (6.2 mmoles) of(R)-2-pyridinemethanamine,N-[2,6-bis(1-methylethyl)phenyl]-α[2-(1-methyl)phenyl]-6-(1-naphthanlenyl)and 10 mL of dry hexanes. To this solution is added drop wise viasyringe 4.0 mL of 1.6 M n-butyl lithium in hexanes (6.2 mmoles). Themixture is stirred for 1 hour, followed by removal of the solvent underreduced pressure. The product is collected on a frit and dried underreduced pressure. The product, (R)-2-pyridinemethanamide,N-[2,6-bis(1-methylethyl)phenyl]-α[2-(1-methyl)phenyl]-6-(1-naphthanlenyl)lithium, is recovered as a light yellow solid, washed with pentane, anddried under reduced pressure. Yield: 2.69 g (89 percent of theoretical)

To a 100 mL round-bottomed flask containing a magnetic stir bar 2.69 g(5.48 mmoles) of (R)-2-pyridinemethanamide,N-[2,6-bis(1-methylethyl)phenyl]-α-[2-(1-methyl)phenyl]-6-(1-naphthanlenyl)lithium and 50 mL of toluene are combined and stirred until dissolved.To this solution is added 2.069 g (5.48 mmoles) of HfCl₄(DME) and themixture is heated to reflux. After 3 hours of reflux, the solution iscooled, 5.9 mL of 3.0 M MeMgBr in Et₂O (19.19 mmoles) are added, and themixture allowed to stir for 3 hours. The solvent is removed, and thesolid extracted with toluene, filtered through diatomaceous earth filteraid, and the toluene removed under reduced pressure to give the desiredproduct as a light yellow solid. Yield: 2.70 g (71 percent oftheoretical)

Cocatalyst—methylalumoxane (MAO) (EURECEN™ AL 5100-10T, availablecommercially from Crompton Corporation).

Shuttling agent—trimethylaluminum (TMA) present in MAO in an amount ofapproximately 33 percent based on aluminum as determined by ¹H NMR.

Propylene Polymerization Conditions

Propylene is polymerized in a batch reactor at 70° C. in either toluene(∈=2.4) or difluorobenzene (∈=14.3) solvents. Propylene is supplied ondemand to maintain the indicated concentration in the reactor. Thereaction is terminated by addition of methanol at low yield to avoidmass transfer effects in viscous solutions and maintain concentration ofshuttling agent nearly constant.

Runs 1-7 employ a racemic mixture (Rac-1) of the foregoing metalcomplex. Run 8 employs the substantially pure R-enantiomer, R1. Resultsare contained in Table 1.

TABLE 1 Hf MAO Al(CH₃)₃ Time, Yield Mw/ Mn Ex. Solvent (μmol) [C₃H₆] M(mmol) (mmol) (min.) (g) Mn (×10³) A* toluene 5.0 0.24 0.60 0.30 130 0.43.8** 2.8 1 C₆F₂H₄ 5.0 ″ ″ ″ 3.5 0.7 1.2 2.0 B* toluene 5.0 ″ 1.20 0.6038 1.0 3.8** 2.2 2 C₆F₂H₄ 5.0 ″ ″ ″ 11 1.0 1.1 1.5 C* toluene 5.0 ″ 2.401.20 56 1.0 1.4 1.8 3 C₆F₂H₄ 5.0 ″ 2.40 ″ 20 1.5 1.1 1.0 4 C₆F₂H₄ 2.5 ″1.20 0.60 17 1.2 1.5 2.3 5 C₆F₂H₄ 10.0 ″ ″ ″ 6.5 0.8 1.1 1.2 6 C₆F₂H₄5.0 0.42 ″ ″ 3.1 0.9 1.2 1.5 7 C₆F₂H₄ 5.0 0.62 ″ ″ 2.0 1.5 1.4 2.1 8C₆F₂H₄ 5.0 0.24 ″ ″ 9.0 1.1 1.2 1.7 *comparative, not an example of theinvention **bimodal molecular weight distribution

The experiment is designed to determine whether chain transfer to thealuminum (catalyzed chain growth, as explained in J. Am. Chem. Soc.2005, 127, 9913-9923) occurs under the conditions tested. Such chaingrowth is necessary for obtaining chain shuttling in the presence of twocatalysts (the two enantiomeric forms of the metal complex). Inexperiment 8, the use of the polar solvent results in extremely narrowmolecular weight distribution polymer having few inversions orregio-errors. Enhanced levels of catalyzed chain growth on aluminum isevidenced by narrowing polydispersity and reduction in average polymermolecular weight of the resulting polymer species for the examples ofthe invention. Direct evidence of the occurrence of multiblock polymerformation (shuttling) is shown by ¹³C NMR spectroscopic analysis of theresulting polymer. The occurrence of inversions in the polymer producedin Example 4 (FIG. 1) is apparent based on the presence of several peaksin the ¹³C NMR, especially at 20.85 ppm, that are absent in the spectrumof the corresponding product made using R-1 catalyst (FIG. 2). Theresults indicate that organoaluminum compounds, specifically tri(C₁₋₄alkyl) aluminum compounds, represented by trimethylaluminum, arerendered more effective as chain shuttling agents, at least with respectto the R- and S-enantiomers of the tested metal complex if a more polarsolvent such as difluorobenzene, rather than a less polar solvent, suchas toluene, is used. Based on this result, it may be predicted thatshuttling agents are much more effective if used in combination with asolvent comprising a polar aprotic compound having a dielectricconstant, ∈, greater than 2.4.

The invention claimed is:
 1. A process for forming a multi-blockcopolymer comprising two or more chemically distinguishable segments orblocks, the process comprising polymerizing one or more olefin monomersin the presence of a chain shuttling agent and a catalyst compositioncomprising: two or more olefin polymerization catalysts capable ofpreparing polymers having differing chemical or physical propertiesunder equivalent polymerization conditions, or a catalyst compositioncomprising at least one olefin polymerization catalyst containingmultiple active catalyst sites capable of preparing polymers havingdiffering chemical or physical properties; characterized in that thepolymerization is conducted in the presence of a solvent comprising apolar, aprotic, organic liquid compound, having a dielectric constantgreater than 2.4.
 2. A process according to claim 1 wherein the polar,aprotic compound is selected from the group consisting of: o-xylene,ethylbenzene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene,1,3,5-trimethylbenzene, isopropylbenzene, 1-methyl-2-ethylbenzene,1,2-diethylbenzene, chlorobenzene, o-dichlorobenzene, chlorotoluene,1-chloroethane, dichloromethane, 1,2-dichloroethane, 1-chloroethene,1-chloropropane, 1,1-dichloroethane, 1-chlorobutane, 1-chloropentane,1-chlorohexane, 1,1,1-trifluoroethane, difluoromethane,trifluoromethane, 1,1-difluoroethane, 1,1,1-trifluororethane,1,1,1,2-tetrafluoroethane, 1,1,1-trifluoropropane,1,1,1-trifluorobutane, 1,1,1-trifluoropentane, 1,1,1-trifluorohexane,1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluorobutane,fluorocyclobutane, difluorocyclobutane, trifluorocyclobutane,pentafluorocyclobutane, fluorocyclohexane, 1,2-difluorocyclohexane,1,3-difluorocyclohexane, fluorobenzene, o-difluorobenzene,m-difluorobenzene, p-difluorobenzene, fluorotoluene, difluorotoluene,1-chloro-1-fluoroethane, 1,2-dichlorofluororethane,dichlorofluoromethane, difluorochloromethane, 2-trifluoromethylpropane,tetrahydrofuran, methyl t-butyl ether, 2-butanone, diethylether,1,2-dimethoxyethane, ethylene glycol dibutyl ether; diethylene glycoldimethyl ether, diethylene glycol dibutyl ether, 1,4-dioxane,chloroform, sulfolane, dimethylformamide, and dimethylether.
 3. Aprocess according to claim 2 wherein the solvent comprises a mixture ofone or more polar, aprotic compounds with one or more aprotic compoundshaving a dielectric constant less than 2.4.
 4. A process according toclaim 2 wherein the polar, aprotic compound is o-xylene, chlorobenzene,dichlorobenzene, fluorobenzene, difluorobenzene, o-chlorotoluene,methylene chloride, diethyl ether, dibutyl ether, tetrahydrofuran,1,4-dioxane, or o-fluorotoluene.
 5. A process according to claim 1 whichis a continuous, solution polymerization.
 6. A process according toclaim 5 conducted at a temperature from 70 to 200 ° C.
 7. A processaccording to claim 1 wherein the shuttling agent is anorganoaluminum-compound containing from 1 to 12 carbons in each organogroup.
 8. A process according to any one of claims 1-6 wherein theshuttling agent is trimethyl aluminum.
 9. A process according to any oneof claims 1-6 wherein the shuttling agent is diethylzinc.
 10. Theprocess of any one of claims 1-7 wherein the polar, aprotic, organicliquid has a dielectric constant from 2.4 to
 50. 11. The process ofclaim 1 wherein the polar, aprotic organic liquid is noncoordinating.12. A process for forming a multi-block copolymer comprising two or morechemically distinguishable segments or blocks, the process comprisingpolymerizing one or more olefin monomers in the presence of a chainshuttling agent and a catalyst composition comprising: two or moreolefin polymerization catalysts capable of preparing polymers havingdiffering chemical or physical properties under equivalentpolymerization conditions, or a catalyst composition comprising at leastone olefin polymerization catalyst containing multiple active catalystsites capable of preparing polymers having differing chemical orphysical properties; characterized in that the polymerization isconducted in the presence of a polar aprotic compound selected from thegroup consisting of: o-xylene, ethylbenzene, 1,2,3-trimethylbenzene,1,3,5-trimethylbenzene, isopropylbenzene, 1-methyl-2-ethylbenzene,1,2-diethylbenzene, 1,2,4-trimethylbenzene, chlorobenzene,o-dichlorobenzene, chlorotoluene, 1-chloroethane, 1,2-dichloroethane,1-chloropropane, 1,1-dichloroethane, 1-chlorobutane, 1-chloropentane,1-chlorohexane, 1,1,1-trifluoroethane, difluoromethane,trifluoromethane, 1,1-difluoroethane, 1,1,1-trifluororethane,1,1,1,2-tetrafluoroethane, 1,1,1-trifluoropropane,1,1,1-trifluorobutane, 1,1,1-trifluoropentane, 1,1,1-trifluorohexane,1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluorobutane,fluorocyclobutane, difluorocyclobutane, trifluorocyclobutane,pentafluorocyclobutane, fluorocyclohexane, 1,2-difluorocyclohexane,1,3-difluorocyclohexane, fluorobenzene, o-difluorobenzene,m-difluotobenzene, p-difluorobenzene, fluorotoluene, difluorotoluene,1-chloro-1-fluoroethane, 1,2-dichlorofluororethane,dichlorofluoromethane, difluorochloromethane, 2-trifluoromethylpropane,tetrahydrofuran, methyl t-butyl ether, 2-butanone, diethylether,1,2-dimethoxyethane, ethylene glycol dibutyl ether; diethylene glycoldimethyl ether, diethylene glycol dibutyl ether, dichloromethane,chloroform, sulfolane, dimethylformamide, and dimethylether.